kỹ thuật mới giải nhanh bài tập hóa học tập 2 vô cơ

Trdn CO so phan tfch kl luong cac n6i dung kien thiic v^ ki nang nam trong khung chuong trinh thi, ca'u true, ma tran d6 thi va cac dang bai tap thucmg gap trong da thi tuyen sinh dai

546.076

K600T NGUYEN NGOC OANH CtJ THANH TOAN

K Y T H U A T M d f l GIAINHANHBAITAP

f

B

TAP 2 HOA H O C V O C O

^ ^ - Tuyen chon cac ky thuat giai nhanh ve

- Tuyen chpn cac ky thuat giai nhanh ve

7 chuyen de hoa v6 ca

- Danh cho hoc sinh Idp 10,11,12 va luyen thi D H - CD

N H A X U A T B A N D A I H O C Q U O C G I A H A N O I

L 6 I N O I D A U

Cac ban ddng nghidp va cac em hoc sinh than m6'n!

Trdn CO so phan tfch kl luong cac n6i dung kien thiic v^ ki nang nam

trong khung chuong trinh thi, ca'u true, ma tran d6 thi va cac dang bai tap

thucmg gap trong da thi tuyen sinh dai hoc, cao dang ciia B6 GD - DT, chung

toi da biSn soan tap sach: "Kithudt moi gidi nhanh bai tap Hod hoc"

Cu6'n sach mof ra m6t co h6i cho giao vian va cac em hoc sinh nhin

nhan lai mot each sau sac va toan dien cac da thi tuyan sinh DH - CD ki tii

khi ap dung hinh thiJc thi trac nghiem, tilr do giao vian c6 dinh hirdng dung

dan cho cac em hoc sinh va miic do kien thiic va cac dang bai tap; con cac

em hoc sinh se vihig vang, tu tin hom de di tran con duomg den c6ng truong

Dai hoc ma minh mo udfc

Tac gia cung khdng quan gili gam vao eu6'n sach cac phuong phap giai

hay, giai nhanh, nham giiip cac em ren luyan ki nang giai nhanh cac dang

bai tap trong di thi tuyen sinh DH - CD Cuon sach se la nguori ban d6ng

hanh than thia't vdri cac em hoc sinh trong qua trinh chinh phuc nhiing dinh

cao vinh quang ciia tri thiic; cuon sach se la tai lieu qui cho cac ban d6ng

nghiep trong qua trinh giang day

Da' cuon sach hoan thian hon, ra't mong nhan duoc su dong gop y kia'n

chan thanh ciia cac ban d6ng nghiep va ciia cac em hoc sinh

Chuc cac em dat dirge nhiau thanh tich cao trong cac ky thi sap t6i

Xin tran trong cam cm ! ' *

T A C G I A

Nhd Sach Kkang Viet xin tran trong giai thieu toi Quy doc gid vd xin long

nghe moi y kien ddng gop de cuon sach ngdy cdng hay hon, bo ich hon Thu xin

gtH ve:

Cty TNHH Mot thanh vien - Dich Vu Van Hoa Khang Viet

71- Dinh Tien Hoang, Fhuimg Dakao, Quan 1, TP HCM

1. DAC D I £ M CIJA CAC NGUVfiN T 6 HALOGEN

ca'u hmh electron 16p

ngoai Cling 2s^2p' 3s^3p' 4s'4p' 5s^-5p' Ban kinh

nguyan tif 0,64A° 0,99A° 1,14A° 1,33A°

Nhiat d6 nong chay ("C)" -219,6 -101,0 -7.3 113,6 Nhiat d6 s6i ("C) -188,1 -34,1 59,2 185,5

Mau sac luc nhat vang luc do nau den tim

Ham iKong (% s6'

II TINH CHAT HOA HOC CUA DON CHAT

- Phan ling toa nhiet manh nha't

- Tac dung v<5ri h^u he't kim loai

- Phan ihig toa nhi^u nhiet

- Tic dung vdi hdu he't kim loai

- Phan umg toa nhiet It hon clo

- Tac dung vdri kim loai cf nhiet d6 cao

hoac cin xiic

ZSZ^C, trong bong t6'i

Phan ihig nS

khi chia'u sang hoac dun nong

Phan ling xay ra

CI, + 2K0H ->KC1 + KCIO + H2O

3 a , + 6 K 0 H

5KC1 + K C I O 3 +3H2O

F2 +

2NaCl,„^„g (.^ij,,

2NaF + O2

Khir duoc Br , I trong dung djch mu6'i:

CI, +2KBr

^ 2 N a a + Br,

Khu duoc r trong dung dich:

Br, +2NaI 2NaBr +1,

Kh6ng Phan ling

Tinh oxi hoa gi5m dan

Kh6ng dilu che' Cho dung djch H X dSc tac dung vdi chat oxi hoa

(MnO,, PbOj, KCIO3, KMn04, ):

4HX + MnO, X , + MnXj + 2H2O Trong

c6ng nghiep

Dien phan nong

2Naa + 2H,0 -> Cij + H2 + 2NaOH

Sau khi phoi nudrc bien d^

la'y NaCl, ph^n con lai chiia nhidu NaBr:

1, Trong phong thi nghiem:

4HX<d) + MnO, .0 • * MnX, + X2 + 2 H , 0 16HX(,, + 2KMn04 > 2 K X + 2MnX2 + X , + SH^O 6HX<a) + KCIO3 -> KCl + 3X, + 3H2O

2(vta All) > I, + 2Naa

vdi dd

AgNOj Khong

A g C U trdng

A g B r i vang nhat

Agli

vang Tdc dung

voi Si02 SiO^ + 4HF ->

SiF4 + 2H2O Kh6ng phan Ung

Thuc te:

3X2 + 2P + 6H2O — ^ >

6HX + 2H3PO,

V M U O I H A L O G E N U A

Mu6'i florua Mu6'i clorua

( C D

Mu6'i bromua ( B r )

Mu6'i iotua

( D

Ti'nh tan

- D6u tan

(trif CaFj, )

- Da s6' tan (trir AgCl, PbCl,, )

- Da s6' tan (li ij AgBr, PbBr2, )

- Da s6' tan

(triif A g l , Hgl,,

Pbl,, Mnlj) Mu6'i

AgX

Tan, mau trSng

Kh6ng tan, mau trang

Kh6ng tan, mau vang nhat

Kh6ng tan, mau vang

Phan ling vori halogen

iJng vod H,S04 dac

CaF2 +

HiSOiij) 250^ C ^

2 H F t + CaS04

r

H C l t + NaHS04

Khong xay ra Khdng xay ra Kh6ng xay ra 2FeCl3 4 2 K I

2 F e a , + 1 ,

+ 2KC1 Phan

- Mu6'i an (NaCl)

- KCl, CaCi,,

NaBr (nude bi^n)

Nal (rong bi^n)

Nhan biet (bang AgN03)

Ag* + I" A g l i

vang

7

- j f ^ CaOCl,

+ H2O

* 3C1, + 6 K O H — ^ 5KC1 + K Q O j + 3 H , 0

* Di6n phan dung dich KCl 2 5 % a n h i a d6 70°C - 75°C

* 6C1, + 6Ca(OH),

— - > Ca(C103), + 5CaCl, + 6 H , 0

Ca(C103)2 + 2KC1 2KC103i + C a a 2

- Kem ben nhifit:

- XiJr ly chat d6c, tinh che' dSu mo

- Thudc n6, ditm

- Diiu che O, trong

phong thf nghidm

B C A C D A N G B A I T A P T R O N G D E T H I T U Y J ^ N S I N H D H - C D

Dang 1: Xdc dinh chat (halogen, muoi halogenua, kim loqi)

1 L i thuyet van dung va phuomg phap giai:

* D6' giai cac bai tap dang nay c6 th^ sir dung cac phuomg phap giai nhanh:

Phuong phap xac dinh chat dua vao cong thiirc tinh phan tur khoi: Gia six c6

chat cho electron la A Ta c6:

m

ke -.k

Vay: m

M A ^ ' ne(cho)

Trong do: m^: Khd'i lucmg chat A (gam)

M ^ : Khd'i luong mol chat A (gam) k: s6' electron do m6t nguyen tir A nhucmg n^ (cho)- s6' mol electron do toan bo luong chat A nhircJng \ + Dua vao cac dir ki^n bai ra cho, xac dinh diroc cac dai lirong m^, k, n^fcho)-

+ Tinh gia tri M ^

+ Tir phan tir khoi xac dinh duoc cha^ cin tim f

Phirong phap t r u n g binh: C6ng thiic tinh nguyfin tir kh6'i trung bmh ciia hai

— m kim loai lidn tife'p trong ciing mot nhom A: M = hh

^hh

It

+ Tinh cac luong chat da cho trong bai ra

+ Viet phuong trinh hoa hoc (so d6 hoa hoc) six dung ki hi6u trung binh

+ Tinh dai lucfng trung binh thich hop

+ Rut ra kd't luan va tinh cac dai luong theo ydu c^u

Phuong phap bao toan electron: Trong phan umg oxi hoa khir, t6ng s6' mol electron do chat khir cho phai diing bang t6ng s6' mol electron do chait oxi hoa nhan:

E e (cho) = S e (nhan) n , h „ N , ,ho = n„hj„ N , „^,„

Trong do: n^ho- "nhan l^n 'ifcrt la s6' mol nguyen tir chat nhircmg, nhan electron (s6' mol nguyen tir chat khir, chat oxi hoa)

N c c h o N , „hj„ \in luot la s6' electron m6t nguyen tur chat khir nhuomg, m6t nguyen tijr chat oxi hoa nhan

+ Viet cac qua trinh oxi hoa, qua trinh khir (kh6ng cin vie't phuong trinh phan

ling oxi hoa - khir)

+ Dat in, dua vao djnh luat bao to^n electron lap duoc phuong trinh dai s6'

Giai he phuong trinh, xac dinh duoc M => chat cin tim

Q

- Phuong phap bao loan khoi lucmg: Trong mdt phan ung hoa hoc, tdng khO'i luong

ciia cac cha't san phsim bang long khO'i liromg cua cac chat tham gia phan ling

Gia sir c6 phan ung: aA + bB cC + dD

I h e o djnh luat bao toan kh6'i luong ta c6: niA + nig = nic +

Ap dung: Trong mot phan ung, c6 n cha't {ki ca chat phan ling va san pha'm), n6'u

biet kh6'i luong ciia (n - 1) cha't thi tinh duoc khd'i lucmg cua ch&t con lai

* Mot s6' n6i dung cin chu y:

- Cac k i m loai c6 nhieu hoa tri (Fe, Cr, ) tac dung voi CI2, axit HCl tao ra mu6'i

clorua k i m loai C O hoa tri khac nhau: ' " "

2Fe + 3 a - > 2FeCl3

Fe + 2HC1 -> FeQ, + H ,

- Cac dung dich mudi halogenua nhu mu6'i clorua, bromua, iotua d^u tac dung voi

A g N O j , con muoi florua khong tac dung duoc voi dung djch AgNO,:

NaF + A g N O j : Khong xay ra

NaCl + A g N O j A g a i + NaNOj

NaBr + A g N O j ^ A g B r i + NaNO,

Nal + A g N O , A g l l + NaNO,

V i vay cac bai tap h6n hop mu6'i halogenua tac dung vdri dung dich A g N O j tao

ra ke't tiia cSn chia hai trucmg hop d^ giai

2 Cac t h i d u m i n h hoa:

Thidu 1: Hoa tan hoan toan 1,1 gam h6n hop gom m6t k i m loai kiim X va m6t

k i m loai ki6m thd Y (Mx < My) trong dung djch H C l du, thu duoc 1,12 lit khi

Thidu 2: Cho dung djch chiJa 6,03 gam hdn hop g6m hai mudi NaX, NaY (X, Y

la hai nguyen to c6 trong t u nhien, d hai chu k i lien tiep thu6c nhom V I I A , sd

hieu nguyen tir < Zy) vao dung dich A g N O j (du), thu duoc 8,61 gam ke't

tua PhSn tram khdi luong ciia NaX trong hdn hop ban ddu la

A 47,2% B 52,8% C 58,2% D.41,8%

(Trich De thi tuyen sinh Dai hoc khoi B)

Hu&ng ddn gidi

Trudmg hcrp 1: Hai mudi NaX va NaY d^u tao ke't tiia vdfi AgNO,

Dat cong thiic chung ciia 2 mudi la N a X :

N a X + A g N O j -> A g X 4- + NaNO,

(23 + X ) g ( 1 0 8 + X ) g 6,03 g 8,61 g '

Ta c6: (23 + X) 8,61 = 6,03 (108 + X) X = 178 (khdng c6 halogen nao c6 trong t u nhien ma c6 M > 178 => loai truong hofp nay)

Tru&ng hop 2: X la flo, Y la clo: i

Goi X , y \in luot la sd mol ciia NaF, NaCl

-Theo bai ra, ta c6: 42x + 58,5y = 6,03 (1) ' J 4 i

NaF + A g N O j > khdng xay ra NaCl + A g N O j > A g C U + NaNOj

y y (mol)

Ta c6: 143,5y = 8,61 y = 0,06 (2) TCr ( 1 , 2) ta c6: x = 0,06; y = 0,06

6,03 Dap an diing la D

Thi du 3: Hoa tan hoan toan 6,645 gam hdn hop mudi clorua ciia hai k i m loai

ki^m thudc hai chu ky ke' tiep nhau vao nude duoc dung dich X Cho toan bo dung djch X tac dung hoan toan vdi dung dich A g N O j (du), thu duoc 18,655 gam ke't tiia Hai k i m loai ki6m tren la

A R b v a C s B N a v a K C K va Rb D L i va Na

(Trich de tuyen sinh Cao dang - Khoi A) Hu&ng ddn gidi

K6t tiia la AgCl: sd mol AgCl = = 0,13 (mol) •

K i hieu chung hai mudi clorua la MCI

MCI + A g N O , ^ AgCl i + MNO3

Thi du 4: Di hoa tan hoan loan 6,4 gam h6n hop g6m k i m loai R (chi c6 hoa trj

II) va oxit cua no cdn viira dii 400 ml dung dich HCl I M K i m loai R la

loai R la M g

Dap an diing la

Thi du 5: Cho 1,9 gam h6n hop mu6'i cacbonat va hidrocacbonat cua kim loai

ki^m M tac dung he't v6i dung dich HCl (du), sinh ra 0,448 1ft khi ( 0 dktc)

Thi du 6: Cho k i m loai M tac dung v6i C I , duoc mu6'i X; cho k i m loai M tac

dung vdfi dung dich HCl duoc mu6'i Y Ndu cho kim loai M tac dung vdi dung

dich mu6'i X ta cung duoc mu6'i Y K i m loai M c6 th^ la

Thi du 7: X la kim loai thu6c phan nhom chinh nhom I I (hay nhom I I A ) Cho 1,7 gam h6n hop g6m kim loai X va Zn tac dung vdi luong du dung dich HCl, sinh ra 0,672 lit khi H j (d dktc) Mat khac, khi cho 1,9 gam X tac dung v6i

luong du dung djch H^SO^ loang, thi thi tich khi hidro sinh ra chua d€n 1,12

Thi du 8: H6n hop X g6m M3CO3, MHCO3 va M Q ( M la kim loai ki^m) Cho

32,65 gam X tac dung vijra dii vofi dung dich HCl thu duoc dung djch Y va c6

17,6 gam CO, thoat ra Dung djch Y tac dung vdi dung dich A g N O j du duoc

100,45 gam ket tiia K i m loai M la

A R b B Na C L i D K

Hu&ng ddn gidi

S6 mol khi CO,: nco^ = I M = o,4 (mol)

2 44 S6' mol ke't tua AgCl: n^gci = 100,45 /143,5 = 0,7(mol)

Goi X, y , z Idn luot la s6' mol M^COj, MHCO3, M C I trong 32,65 gam X

Bao toan cacbon ta c6: x + y = 0,4 Bao toan clo ta c6: 2x + y + z = 0,7

Ap dung djnh luat bao toan khd'i luong ta c6:

13

Thi dti 9: H6n horp X chira dong ihbi hai mu6'i natri cua hai halogen lien tife'p

trong bang tuSn hoan La'y mot luorig X cho tac dung vira dii \6'\0 m l dung

dich A g N O , I M thi thu duoc 15 gam ket tiia C6ng thiJc phan tijf ciia hai muoi

trong X la (cho F = 19; Q = 35,5; Br = 80; I = 127; Na = 23)

A NaF va NaCl B NaBr va Nal

C NaCl va Nal D NaCl va NaBr

Hu&ng dan gidi S6 mol A g N O j : n^gNOj = 0 - ' ("loO •

' Trirorng hop 1: Hai halogen d^u tao diroc kfi't tiia v6i A g N O j

Dat c6ng thufc chung ciia mu6'i la N a X

vay hai mu6'i trong X la NaCl va NaBr

=> "^Agca =0.1.143,5=14,35(gam) ^1.5(gam)

loai tnrcmg hop nay

Thi du 10: Cho 19 gam h6n hop b6t g6m k i m loai M (hoa tri khdng d6i) va Zn

(ti IS mol tirong umg 1,25 : 1) vac binh dirng 4,48 lit khi CI, (dktc), sau cac

phan ufng hoan toaii thu duoc h6n hop chat rSn X Cho X tan h6't trong dung

dich H Q (dir) tha'y c6 5,6 lit khi H , thoat ra (dktc) K i m loai M la

A Na B Ca C M g D A l

Huatng ddn gidi

S6'mol khi CI, va H , Mn lirot la: n ^ j = 0 , 2 ( m o l ) ; n^^^ = 0 , 2 5 ( m o l )

Dat X la s6' mol Z n => s6' mol k i m loai M la 1,25x

T a c o : 6 5 x + M.l,25x = 19 ( l ) V ' , ' Theo nguydn t i c bao toan electron ta c6:

Gia tri phii hop la n = 2 => M = 24 (Mg) Dap an diing la C • >

3 Cac bai tap t u luyen:

Cku i : K i m loai nao sau day tac dung voi dung djch HCl loang va tac dung vdi khf

CI3 cho cung loai mu6'i clorua k i m loai?

<-15

C&u 2: Cho m6t lirong don chat halogen tac dung h6't vdd magie thu dirge 19 gam

magie halogenua Cung lugng don chat halogen do tac dung h6t vdi nhom tao ra

17,8 gam nh6m halogenua Kh6'i lirgng don chat halogen da phan ung la

A 8,0 gam B 14,2 gam C 19,0 gam D 7,1 gam

Dap an dung la B

C&u 3: Cho 1,03 gam mu6'i natri halogenua (A) tac dung vdi dung dich AgNO, du

thi thu dirge mot kd't tua, ke't tiia nay sau khi phan iJng hoan loan cho 1,08 gam

bac C6ng thiic ciia mu6'i A la

A NaF B.NaCl C NaBr D Nal

Hu&ng ddn gidi

I no

Sd'molAg: n ^ = — - 0 , 0 l ( m o l )

Dat mu6'i natri halogenua la NaX

PTHH: NaX + AgNOj > AgXi + NaNOj

0,01 < 0,01 (mol) AgX Ag + -X2

C&u 4: Cho dung djch chura 6,79 gam h6n hop g6m 2 mu6i K X , K Y (X, Y m 2

nguydn t<5 c6 trong tu nhifin, 6 hai chu ki lifin tie'p thu6c nhom V I I A , s6' hidu

Zx < ZY) vao dung dich AgNO, dir thu dugc 8,61 gam kd't tiia Th^nh ph^n % kh6'i lugng ciia KX trong h6n hop ban d^u la

Cau 5: M6t h6n hcyp X g6m 3 muoi halogenua ciia kim loai natri nang 6,23g hoa tan hoan toan trong nuoc dugc dung dich A Sue khi clo du vao dung dich A roi c6 can hoan toan dung dich sau phan ung dugc 3,0525g mu6'i khan B La'y m6t nua lucmg mu6'i nay hoa tan vao nude r6i cho phan ihig voi dung djch AgNO, du thi thu dugc 3,22875g ket tiia Tim c6ng thiic ciia cac mu^i va tinh % theo khd'i lugng m6i mu6'i trong X

Hu&ng ddn gidi

Gia sii lugng mu6'i khan B thu dugc sau khi cho clo du vao dung djch A chi c6 NaCl-> n^aci = - ^ ^ = 0,0522 mol '

58,5 *'* NaCl + AgNO, A g a i + NaNO, (1)

* 3 22875

Theo (1) -> n^^ci = "Aga = -2 = 0,045 mol < 0,0522 mol t

Do do, mu6'i khan B thu dugc ngoai NaCl con c6 NaF

Vay trong h6n hgp X chira NaF, khd'i lugng NaF:

Goi c6ng thiJc chung ciia hai mutfi halogen c6n lai 1^: NaY

-> ph^i c6 m6t halogen c6 M > 106,11 - » d6 iot • v ^tf

Vay c6ng thiic cua mud'i thiJ 2 Ilk Nal

Dod6c6haitrucmghop: " ' « f-*'

* Tru&ng hop 1: NaF, NaCl vk Nal

Goi a, b Mn lugt la s6 mol ciia NaQ Nal #

6,23

%NaI = 141-100% = 60,19%; %NaF = 6,74%

6,23

C&u 6: Hô tan 1,086 gam mu6'i chiJa oxi ciia clo vdi m6t kim loai ki^m v^o nude,

axit hod dung djch bang axit H2SO4 loang rdi them tiT dung dich K I vao cho dén

khi kh6ng c6n I , thoat ra thi thu duoc 6,096 gam I2 CQng luong mu6'i trdn dem

nhiet phan hoan tôn sau phan ihig con lai a gam mu6'ị

1 Xdc dinh c6ng thiic mu6'ỉ ' ( ' )

2 Tfnhả

Hu&ng đn gidi

1 C6ng thiic mu6'i c6 dang RQO, (x = 1 -> 4)

Phuong trinh phan umg:

Rao, + 2xKI + xH,S04 ^ RQ + xlj + xK,S04 + xH^O

18

S6' mol I2 = ^ : ^ = 0 , 0 2 4 ( m o l ) Theo phirong trinh s6' mol R Q O , = 0,024

R+35,5+16x = l,086x

0,024 R=29,25x~35,5 Thoa man vdi x = 2; R = 23, kim loai k i i m la Na; mu^i \h NaQỘ

2 Phuong trinh phan umg nhifit phan mu6'i:

.0 NaClOj — ^ NaQ + O,

Theo phuong trinh s6' mol NaQ = s6 mol NaQOj = 0,012

=> Kh6i luong NaQ = 0,012 58,5 = 0,702 g

Cau 7: Cho 50 gam dung dich M X (M la kim loai ki6m, X 1^'halogen) 35,6% tac dung vcri 10 gam dung dich AgNOj thu duoc két tuạ Loc kfít tiia, duoc dung djch nude loc Biét n6ng d6 M X trong dung djch sau thi nghidm giam 1,2 ISn so vdi n6ng d6 ban đụ

mu6i M X la L i a

19

Dang 2: Xdc dinh luffng chat (tham gia, sdn phdm, cdn Iqi sau phan itng)

vd thdnh phan cdc chat trong hdn harp

1 L i thuy^'t v$n dung va phuong phap glai:

* Cac phucfng phap giai nhanh duoc sir dung:

- Phuong phap bao toan electron: Trong phan ung oxi hoa khu, t6ng s6' mol

electron do chat khu ciio phai diing bang tdng s6' mol electron do chat oxi hoa nhan:

S e ( c h o ) = E e ( n h a n ) => iicho-Necho = n„hi:, N,„h,„

+ Viet cac qua trinh oxi hoa, qua trinh khijf (khong cin vie't phucmg trinh phan

ling oxi hoa - khir)

+ Dat ^n, dua vao djnh luat bao toan electron lap duac phuong trinh dai s6'

+ Giai he phircmg trinh, xac djnh cac dai luong theo yfiu ciu ciia bai toan

- Phuong ph^p bao toan khoi luong: Trong m6t phan ung hoa hoc, tdng kh6'i luong

ciia cac chat san ph^m bang t6ng kh6'i luong ciia cac chat tham gia phan ung

A p dung: Trong m6t phan ung, c6 n chat (k^ ca chat phan ung va san ph^m),

ne'u bie't kh6'i luong cua (n - 1) chat thl tinh duoc khd'i luong ciia chat con lai

- Phuong phap su dung cac cong thurc giai nhanh:

+ C6ng thiic tmh kh6'i luong mu6'i clorua thu ducfc khi hoa tan hit h6n hop kim

loai bang dung dich HCl: m„„,„, = m^i^^,^ + ^ I H H J

+ C6ng thiirc tinh kh6'i luong mu6'i clorua thu duoc khi hoa tan h6't h6n hcyp oxit

k i m loai bang dung djch HCl: m,|„„, = mh4„ + 27,5nHci

* M 6 t s 6 ' c h u y :

- Fe304 khi giai bai tap c6 the qui doi thanh: FeO.Fe^Oj

FejO^ + 8HC1 - > 2FeCl3 + FeCl, + 4 H , 0

Do do h6n horp Cu, Fe304 c6 tha' bi tan hat trong dung djch HCl (Cu khdng tac

dung vdi dung djch HCl nhung bj hoa tan boi dung dich FeClj):

Cu + 2Fea3 CuCU + 2 F e a 2

- Mudi clorua bj oxi hoa boi KMn04/H2S04:

IOAICI3 + 6KMn04 + 24H2SO4 5Al2(S04)3 + 3K,S04 + 6MnS04 + 24H2O

- K i m loai Fe (hoac Cr) tac dung voi CU va axit HCl tao ra san ph£m mu6'i clorua

khac nhau: 2Cr + 30, -> 2CrCl3

Cr + 2HC1 CTCXJ + H ,

2 Cac thi du minh hoa: ;

Thidu 1: Cho 42,4 gam h5n hcrp g6m Cu va Fe304 (c6 ti le so mol tuong ung la

3 : 1) tac dung vori dung dich HCl du, sau khi cac phan ung xay ra hoan toan

c6n lai m gam chat ran Gia trj ciia m la

+) Tuy Cu kh6ng tan trong HCl, nhung bj hoa tan bod FeCl,

— —~— t '

Thi du 2: Hoa tan hoan toan 2,7 gam h6n hop X g6m Fe, Cr, A l bang dung djch HCl du, thu duoc 1,568 lit khi H j (dktc) Mat khac, cho 2,7 gam X phan ling hoan toan vdi khi du, thu duoc 9,09 gam mud'i Khd'i luong A l trong 2,7

gam X la bao nhiau?

A 1,08 gam B 0,27 gam C 0,81 gam D. 0,54 gam

(Trich de tuyen sink Cao dang nam 2012 - Khoi A) Hu&ng ddn gidi

Theo bai ra: Hjj^ =0,07 (mol) Goi x,y,z 1& luot la so mol Fe,Cr,Al trong X

A1 + - C 1 2

2 ^ z—•l.Sz

Thi du 3: H6n hap X c6 khd'i luong 82,3 gam g6m KQOj, € 3 ( 0 0 3 ) 2 , CaQj va

K Q Nhiet phan ho^n to^n X thu duoc 13,44 lit O2 (dktc), chat ran Y g6m

CaQz va K C l Toan b6 Y tac dung vira du vdi 0,3 lit dung djch K2CO3 IM thu

duoc dung dich Z Luang K C l trong Z nhi^u ga'p 5 15n luong K C l trong X

PhSn tram khd'i luong KCl trong X la

A 18,10% B 12,67% C 29,77% D 25,62%

(Trick dSthi tuyen sink DH khoi A) Hu&ng ddn gidi

Phuong phap bao toan kh6'i luong:

Theo bai ra: = 0,6 (mol); nK2C03 = 0,3 (mol)

Sodd phan utig: X '° > Y + Oj

Theo dinh luat bao toan khd'i luong ta c6:

99

fhi du 4: D6't 16,2 gam hOn hop X g6m Al va Fe trong khi CI2 thu duoc h6n hop

chat ran Y Cho Y vao nude du, thu duoc dung dich Z va 2,4 gam kim loai

Dung dich Z tac dung duoc vdfi t6i da 0,21 mol KMn04 trong dung dich H2SO4 (kh6ng tao ra SO2) Phdn tram khd'i luong ciia Fe trong h6n hop X la

Thidu 5: D6t chay hdn hop g6m 1,92 gam Mg va 4,48 gam Fe vdi h6n hop khi

X g6m clo va oxi, sau phan dug chi thu duoc h6n hop Y g6m cdc oxit va mu6'i clorua (khdng c6n khi du) Hoa tan Y bang m6t luong vfira dii 120 ml dung dich HCl 2M, thu duoc dung dich Z Cho AgNOj du vao dung dich Z ,

thu duoc 56,69 gam kd't tia Phin tram th^ tfch ciia clo trong h6n hop X la

A 51,72% B 76,70% C 53,85% D 56,36%

(Trich di thi tuyen sink DH khdj B) Hu&ng ddn gidi ^ Se> mol cac cha't: n^^ = 0,08 (mol); np^ = 0,08 (mol); nna = 0,24 (mol)

Goi x, y, z Idn luot la s6' mol ciia Cl2,02 va Ag"^ (tao ra Ag) I*' Cac qua trinh nhucmg nhan electron:

23

Thidu 6: Cin t6'i thi^u bao nhidu gam NaOH (m,) va (mj) de' phan ling hoan

tokn vdi 0,01 mol CrQj Gia tri cua m, va mj iSn luot la

ChU v.- mat ly thuye't c6 thi c6:

14NaOH + 2CrCl3 + 3CI2 ^ 12NaCl + Na2Cr207 + 7H2O

0,07 < - 0,01 0,015(mol)

=> m, = 0,07.40 = 2,8(g); m2 = 0,015.71 = l,065(g)

Thi du 7: Cdn a mol K^CrjO, va b mol HCI d^ diiu che' duoc 3,36 lit di^u

kifin chudn Gia tri a v l b iSn lirot la

Thi du 8: Cho m gam h6n hop X g6m FeO,Fe203,Fe304 vao m6t luong vira du

dung djch H Q 2M, thu diroc dung dich Y c6 ti 16 s6' mol Fe^"" va Fe^^ la 1: 2

Chia Y thanh hai ph^n bang nhau C6 can phSn m6t thu duoc m, gam mu6'i khan Sue khi clo (du) vao phfo hai, c6 can dung dich sau phan ling thu duoc

m2 gam mu6'i khan Bid't mj - m, = 0,71 Th^ tich dung djch HCI da dung la

Ta c6: n^^c\2 = "FeO = x (mol); npecij = 2nFe203 = 2y (mol)

V i ti le s6 mol Fe2+ va Fe^* la 1 : 2

=>nFeCi2 :"FeCi3 = 1:2 => X : 2y = 1:2 =>x = y

CI2 + 2FeCl2 2FeCl2

x / 4 < - x / 2 x / 2 TheobMra: m j - m , =0,71

Thi du 9: Cho 3,16 gam KMn04 tac dung voi dung dich HCI dac (du), sau khi

phan ling xay ra hoan toan thi s6' mol HCI bi oxi hoa la

A 0,10 B.0,16 C.0,02 D 0,05

(Trich de tuyen sinh Cao dang khoi A)

Theo b l i ra: n KMn04 = = 0,02 (mol)

Hu&ng ddn gidi

3J6

158

25

Cdchl: Bao toan electron

Cdchl: Sir dung phuong trinh ion rut gpn:

2Mn04 + I6H+ + lOCF ^ IMn^^ + 5CI2 + 8H2O

+ Bj oxi hoa (chat khijr): 2C1 -> Clj + 2e

+ M6i tnrcmg (tao mu6'i clorua)

Do do kh6ng ti'nh diroc luong H Q bi oxi hoa theo phucfng trinh phan ling dang

phan i\X

Thi du 10: Didn phan dung dich CuQj voi difin cue tro, sau m6t thoi gian thu

duoc 0,32 gam Cu b catot va m6t lucfng khi X b anot. HSfp thu hoan toan

lugtng khf X tr^n vao 200 ml dung dich NaOH (d nhiet d6 thucmg) Sau phan

ung, ndng d6 NaOH con lai la 0,05M (gia thie't th^ tich dung dich kh6ng thay

ddi) N6ng d6 ban ddu ciia dung dich NaOH la

=> T6ng s6' mol NaOH ban ddu:

2^nN,OH (bandiu) = HNaOH (p/x) + "NaOH (du) = 0,01 + 0,01 = 0,02 (mol)

0,02 Vay n6ng do ban ddu ciia dung dich NaOH: CN,OH (ban d4u) =

Dap an diing la C

0,2 = 0,1M

3 Cac bai tskp tu luyen:

C&u 1: Cho 2,13 gam h6n hop X g6m ba kim loai Mg, Cu \k A l 6 dang b6t tac

dung hoan toan \cn oxi thu dugc h6n hop Y g6m cac oxit c6 kh6'i luong 3,33

gam The' ti'ch dung dich HCl 2M vifa dii d^ phan umg he't voi Y la

= > HHCI = n ^+ = 0,15 (mol) , _

vay: HO = ^ = 0,075 lit = 75 (ml)

Dap an diing la C

C^u 2: Di hoa tan hoan toan 2,32 gam h6n hcpfp g6m FeO, Fe304 v^ FcjO, (trong

do s6' mol FeO bang s6' mol Fe^O^), cSn diing vita dii V lit dung djch H Q I M

Gia trj cua V la

A 0,08 B.0,16 C.0,18 D 0,23

(Trich De thi tuyen sinh DH khoi A) Hu&ng ddn gidi

V i s6' mol FeO bang s6' mol FcjOj ndn qui d6i h6n hap thanh Fe304 (FeO.FcjOj):

S6 mol Fe304: np,304 = ^ - 0,01(mol) ^

PTPIT: Fe304 + 8HC1 > FeCl^ + 2FeCl3 + 4H2O

0,01 -> 0,08 (mol) Suy ra th^ ti'ch dung djch HCl cSn dung: V,<,„c, = ^ = 0,08 (lit) ' E>ap an diing la A

Cau 3: De oxi hod hoan to^n 0,01 mol C r a , th^nh K 2 C r 0 4 bang CI, khi c6 mSt

KOH, lirong t6'i thi^u va KOH tucmg ling Ik

A 0,015 mol va 0,04 mol B 0,015 mol va 0,08 mol

C 0,03 mol va 0,04 mol C 0,03 mol va 0,08 mol

(Trich De thi tuyen sink DH khoi A) Hudng ddn gidi

PTPU": ICrGj + 3 0 , + 16KOH ^ 2K2Cr04 + 12KC1 + 8 H , 0

Cau 4: Nung h6n hop b6t g6m 15,2 gam CTJOJ va m gam A l & nhifit d6 cao Sau

khi phan ihig hoan toan, thu duoc 23,3 gam h6n hop ran X Cho toan b6 h6n hop

X phan ling vdi axit HCl (du) thoat ra V lit khi H2 (6 dktc) Gia tri ciia V la

So 6.6 phan ling: A l + CfjOj -> H6n hop sau phan ihig

S6' mol Cr^O,: nc^o3 = T T T = 0, '(mol)

Zn H2 = 0,15 + 0,2 = 0,35 (mol)

=> =0,35 22,4 = 7,84 (lit)

Dap an dung la C

Cau 5: Cho 9,12 gam h6n hop g6m FeO, FcjOj va Fe304 tac dung vdi dung djch

HCl (du) Sau khi cac phan urig xay ra hoan to^n, duoc dung djch Y, c6 can Y thu diroc 7,62 gam FeClz va m gam FeQ, Gia trj ciia m la

Cau 6: Cho m gam h6n hop X gdm A l , Cu vao dung dich HCl (du), sau khi V.€x

thiic phan ling sinh ra 3,36 lit khi (o dktc) Neu cho m gam h6n hop X trSn vao

mot luong du axit nitric (dac, nguoi), sau khi ka't thuc phan umg sinh ra 6,72 lit

khi NO, (san phdm khir duy nha't, do 6 dktc) Gia tri ciia m 1^

A l + HNOj^ij, „g„oi) > bj thu d6ng hoa

Cu + 4HN03,<,i,) > Cu(N03)2 + 2NO2 + 2H2O

y

n NO2 = 2y = 0,3 => y = 0,15 (mol)

Vay m = niA, + mc„ = 0,1.27 + 0,15.64 = 12,3 (g)

Dap an dung la C

Chu v: * A l , Fe, Cr bi thu d6ng hoa trong HNO3 dSc, ngu6i

Cau 7: Dung dich X chiia h6n hop g6m NazCOj 1,5M K H C O 3 I M ^fh6 tir tv?

timg giot cho de'n hfi't 200 ml dung djch HQ I M v^o 100 ml dung djch X, sinh

ra V 1ft khi (6 dktc) Gia trj cua V la • ,vi'

A 4,48 B 1,12 C.2,24 D 3.36

^ ^'l ' * ^ (Trich Be thi tuyen sinh Dai hoc khd'i A)

Hu&ngddngim Theo b^i ra: n^a = 0,2.1 = 0,2 (mol); n NajCOa = 0,1.1,5 = 0,15 (mol)

Khi nho tir tCr dung djch HQ (H") vao X thi:

-% Na^COj + HCl > NaCl + NaHCO,

0,15 > 0,15 > 0.15 (mol)

Sau phan ling nay, luong HCl con lai la: n^am = 0,2 -0,15 = 0.05 (mol)

Do d6 xay ra qua trinh:

H C O 3 + H* > CO:t + H2O

0.05 < 0.05 — > 0,05 (mol)

v a y V = Vco2 = 0,05.22,4 =1.12 (lit)

Dap an dung la B

c a u 8: Khi cho 100 ml dung djch KOH I M vao 100 ml dung djch HCl thu duot

dung djch c6 chiia 6.525 gam chat tan Ndng d6 mol (hoac mol/1) ciia H Q trong

dung djch da dung 1^

A.0.75M B.0.5M C I M D 0.25M

(Trich Dim tuyen sinh Cao dang khoi A) Huong ddngidi

Theo bai ra: U K O H = 0,1.1 = 0.1 (mol)

Phuong trinh phan ung: KOH + HQ > K Q + HjO

Gia thid't KOH phan img he't => n^a = I I K O H = 0.1 (mol)

=> mKc, = 0,1 74,5 = 7,45 (g) > 6.525 (g)

Suy ra, KOH phan irng chira he't (HQ he't chat tan c6 K Q v^ KOH)

Goi X , y Idn luot 1^ s6' mol KOH phan ling voi HCl va c6n du

Theo b i i ra ta c6: x + y = 0.1 (1)

- i 74.5 X + 56 y = 6,525 (2)

Tir (1 2) ta giai ra duoc x = 0.05

v a y CM(„a, = x/0,1 = 0.05/0,1 = 0.5M

Dap &n dung la B

c a u 9: Hoa tan he't 7,74 gam h6n hop b6t Mg, A l b ^ g 500 ml dung djch h6n hop

HQ I M va H2SO4 0,28M thu dugc dung djch X va 8,736 lit khi H2 (Jb dktc) C6

can dung djch X thu duoc luong mu6'i khan la

A 77,86 gam B 25.95 gam C 103,85 gam D 38,93 gam

(Trich Di thi tuyen sinh Cao ddng khd'i A) Hudng ddn gidi

Theo b^i ra: n^a = 0.5 1 = 0.5 (mol);

nH2S04 = 0.5 0.28 = 0,14 (mol); n H ^ = 8.736/ 22.4 = 0,39 (mol)

Ta thafy = " 8 2 8 0 4 + ^na^ => Axit phan ling v&a he't voi kim loai

Sord6: Kim loai+ Axit > mud'i + Hj ''^ ' ,

=>m = 7,74 + 0,5.36.5 + 0.14.98 - 0,39.2 = 38.93 (gam)

Dap An diing 1^ D

Cau 10: Cho m gam b6t A l vao c6c chura V lit dung djch NaOH 2M, sau phan ling

hoan tohn cho tiep dung djch HCl vao c6c 66 de'n khi cha't ran tan he't thafy cdn

diing 800 ml dung djch H Q I M va c6 3.36 lit khi thoat ra (cj dktc) Gia tri cua m

va V lin luot la

A 6.075 va 0.0625 B 6.075 va 0,2500

C 7,425 va 0.0625 D 3,375 v^ 0,2500

Hu&ng ddn gidi

TTieo bM ra: H H C I - 0.8.1 = 0.8 (mol)

Khi thoat ra la H^: n^^^= 3.36 / 22.4 - 0.15 (mol)

2Al + 2NaOH + 6H2O ^ 2NaAI (OH)^ + 3H2 t

X -> x -> x (mol) NaAl(OH)^ + 4HC1 NaQ + AICI3 + 4H2O

X - > 4x 2A1 + 6HC1-).2A1C13+3H2 t

y - > 3 y - ) l,5y

T u v , r4x + 3y = 0.8

Theobairataco:-^ ^ ix> x = 0.125; y = 0.1

[1.5y=0.15 Vay: m = (x + y).27 = (0,125 + 0,l).27 = 6.075(g) J

V = x/2 = 0,125/2 = 0,0625(1)

J > 5 p d n d u n g l a A

C&u 11: H6n h<?p M g6m cac kirn loai Cr, A l , Mg, Cu La'y 50 gam M tdc dung von

dung dich HCl du thu duoc 186 gam mu6'i va c6 3,2 gam chat rSn kh6ng tan

Cung la'y 50 gam M tac dung hoan toan vdi khi clo thi thu duoc 199,85 gam

mu6'i Phin tram khd'i luong cua Cr va Cu trong M l^n luot la

Mg + Cl2 - > M g C l 2

C U+ C I 2 ->CuCl2 0,05 -> 0,05(mol)

Ta tha'y: m c u c i j + "^Crcij - mcrCi2 = '^^,85 -186

Cau 12: Hoa tan het 4 gam oxit Fe.Oy c^n diing 52,14 ml dung dich HCl 10%

(d = 1,05 gam/ml) Dd' khii hoa hoan toan 4 gam oxit sat nay dn it nha't th^ tfch

1 y

0 , 1 5 / 2 y 0 , 0 7 5

=>Vco =0,075.22,4 = 1,68 (1ft) ^ ^ E)ap an dung la A

cau 13: Nho ttr tir cho de'n het 400 ml dung dich H Q I M vko 200 ml dung djch

chura d6ng thcri Na^COj I M va NaHCOj I M , kfi't thuc phan ling thu duoc V lit CO2 (dktc) Gia tri ctia V la (cho C = 12,0 = 16, H = 1, Na = 23, Q = 35,5)

Phan iJng: 0,2 <- 0,2 ^ 0,2 Conlai: 0,2 0 0,4

HCl + NaHC03 -> NaQ + CO2 t +H2O Banddu: 0,2 0,4

Phan ling: 0,2 -> 0,2 -> 0,2 Vco2 = 0,2 22,4 = 4,48 (lit) • Dap an diing la A

cau 14: Cho 4,41 gam KjCr.O, vao dung djch HCl dSc, dir Th^ tich khi thoat ra {b

dktc) sau khi ka't thuc phan ling la

A 1,008 lit B 0,336 lit C 1,344 lit D 0,672 lit

15: Hoa hat 2,32 gam h6n hop FeO, Fe304, Fe^O, (trong d6 FeO, Fc.O, c6 s6'

"lol bang nhau) trong 80 ml dung djch HCl I M thu duoc dung djch X Cho X tac dung voi dung dich AgNOj du thi thu duoc bao nhieu gam chat kh6ng tan?

^•16,80 B 11,48 C 1,08 D 12,56

^ =>nFea3 =0.02(mol); npecij =O.OKmol)

FeCl3+3AgN03 >3AgCl I+Fe(N03)3

y F e C l 2 + 3AgN03 — ^ > 2 A g C l i +Ag i +Fe(N03)3

0,01 > 0,02 -> 0,01 (mol) Vay, kh6'i luong chat khdng tan:

^ m = mAgci +mAg =(0,06 + 0,02).143,5 + 0,01.108-12,56(gam)

Dap an dung la D

C^u 16: Cho 17,5 gam h6n hop A l , Zn, Fe tac dung hoan toan vdi dung dich HCl

du thu diroc dung djch X va V lit H , (dktc) C6 can dung djch X thu duoc 53

gam mu6'i khan VSy gia tri cua V la

Dap an dung la C

Cau 17: D^ hoa tan hat h6n hop X g6m Cr^Oj, CuO, Fe304 cin vira du 550 ml dung

djch HCl 2 M , sau phan ling thu duoc dung dich Y M6t nijfa dung dich Y tha'y

hoa tan he't t6'i da 2,9 gam b6t Ni C6 can nifa dung dich Y con lai thi thu duofc

bao nhiau gam mu6'i khan?

A 30,525 gam B 30,8 gam C 61,6 gam D 61,05 gam

Hu&ng ddn gidi

Theo bki ra: H H C I =1,1 (mol); =0,05 (mol)

Goi X , y, z \in luot la s6' mol ciia CrjOj, CuO, Fe304 c6 trong h6n hop X

Cau 18: Kh6i luong t6'i thi^u NaOH Q , d^ oxi hoa hoan t o ^ vdd 0,» ' ;nol

NaCrOz thanh Na2Cr041^ luot la

Cau 19: Ho^ tan hoan to^n m gam h6n hop g6m Na, Ba, K v^o nu6c thu duoc x

gam khi H , Ne'u cho m gam h6n hop trfen tic dung vdd dung djch H Q du, r6i c6

can dung djch sau phan ling thi khd'i luong mud'i khan thu duoc 1^

A (m + 17x)gam B (m + 35,5x)gam

C (m + 142x)gam D (m + 17,75x)gam , ,

35

Ttnwaat mm gtat nhann BTH0irn^srTap7 -Timtanli Toan

Dang 3: Dieu che, tinh che

vd phdn Met cdc halogen vd hap chdi cua halogen

1. L i thuyet vakn dung va phuorng phap giai:

- Dilu ch^ cac halogen trong phong thi nghidm va trong c6ng nghidp:

2NaBr + a2(ve«du) — ^ Br2 + 2Naa

2NaI + Cl2 (w«du) — ^ I2 + 2Naa

Di^u chd' cac hidro halogenua HX:

T h u c te 3X2 + 2P + 6H2O 6 H X + 2H3PO3

f)iiu ch6 cac hop chat c6 oxi ciia clo:

CI2 + 2NaOH(,„j„g) > N a Q + N a Q O + H2O

0 2 + Ca(OH)2(b«„ > CaOClj + H2O

3 0 2 + 6 K O H — ^ 5KC1 + KOOj + 3H2O

6 0 2 + 6Ca(OH)2 — ^ € 3 ( 0 0 3 ) 2 + 5 C a a 2 + 6H2O

2 C a c thi d u m i n h h o a :

'rhidu I Chat diing d^ 1 ^ kh6 khi 0 2 im \h

A NajSOj khan B dung dich H2SO4 dam dac

C CaO D- dung djch NaOH dac

^ (Trick di tuyen sinh Cao dang - Khoi A)

Hu&ng ddn gidi Cha't CO th^ dung di lam kh6 khi 0 2 im phai la: v

+ Chaft hao nude + Chat khdng tac dung vdd O j

Thoa man di^u ki6n tr6n la dung dich H2SO4 dam dac

Dap an dung la B

Thi du 2: C6 4 6'ng nghidm duoc danh s6 theo tu: tu 1, 2, 3, 4 M 6 i 6ng nghifim

chiia m6t trong cac dung dich AgNOj, Z n 0 2 , H I , Na2C03 Bife't rang:

- Dung dich trong 6'ng nghifim 2 va 3 t^c dung duoc vdd nhau sinh ra ch&t khi;

- Dung dich trong 6'ng nghifim 2 va 4 kh6ng phan ling duoc vol nhau

Dung dich trong cac 6'ng nghifim 1, 2, 3 , 4 1 ^ lupt 1^:

^ n g nghifim 3 , 4 \in lupt la Na2C03, Z n Q j

=> 6ng nghiem 1 la AgN03 (dung dich con lai)

Vay 1, 2, 3 , 4 \in lupt la AgN03,HI,Na2C03,ZnCl2

E>^p an diing la B

37

j TM du 3: Kh6ng khi trong ph6ng thi nghiSm bi 6 nhi^m boi khi clo khiJt d6c,

c6 th^ xit v^o khdng khi dung dich nao sau day?

; A Dung dich NH, B Dung dich NaQ

C Dung dich NaOH D Dung dich H 2 S O 4 loang

(Trich detuyen sink Dai hoc khoi A)

i Hu&ng ddn gidi

C6 th^ xit dung dich NH3: 2NH3 + SClj + 6HC1

HC1 + NH3->NH4C1 Ddp dn diing la A

Thidu 4: Trong phong thi nghiSm, ngirori ta thucmg dilu chd'clo bang each

A cho dung dich HCl dac tac dung vdi MnOi, dun nong

B Aitn phan dung djch NaCl c6 mkng ngan

C dien phan nong chay NaCl

D cho F2 d^y Clj ra khoi dung dich NaQ

(Trich De thi tuyen sink DH - CD khoi A) Hu&ng din gidi

Trong PTN, nguod ta thucfng dilu che' khi clo bang each cho cha't oxi hoa manh

(MnOj, K C I O 3 , KMn04, CaOQz, ) tac dung vdri axit clohidric dSc:

4Ha + MnOj — ^ CI2 + M n Q j + 2H2O

6 H a + KQOa > SQj + K Q + m.O

16Ha + 2KMn04 > SCl^ + 2KC1 + 2 M n a 2 + SH.O

2HC1 + C a O a , > CI2 + CaClj + H^O

Chu v; Ne'u chat oxi hoa la Mn02 thi dn phai dun nong, con cha't oxi hoa la

KMn04 , K Q O j hoac CaOClj phan ihig xay ra b nhiet d6 thucmg

Dap an diing la A

Thi du 5: Di nhan biet 3 axit dac, ngu6i: HCl, H2SO4, H N O 3 dung n€ng biet

trong 3 lo mat nhan, ta dung thu6c thif la

Chu y:

Kim loai yd'u (kim loai diing sau H trong day difin hoa, nhu Cu, Ag, ) kh6ng phan ling vdi dung dich H Q

Kim loai yfi'u (Cu, Ag, Hg, ) tac dung vdi H 2 S O 4 dac, tao ra san p h ^ khir la

SO2 (kh6ng mau, miii hac); tac dung vdi H N O 3 dac tao ra san ph^m khii la NO, (mau nau)

fhfduS: Co the phan bidt 3 dung dich: KOH, HCl, H2S04(loang) bang m6t

thu6'c thir la

A gia'y quy tim B A l C BaCOj D Zn

(Trich De thi tuyen sinh DH - CD khoi B) Hu&ng ddn gidi

Chon thu6'c thir la BaC03:

BaCO, + K O H (dd): khdng C O hidn tuomg '

BaCOj + 2HC1 - > BaCh + CO.J + HjO 5 w;

BaCOj + H2SO4 BaS04^ + C O j t + HjO

Dap an diing la C

Thi du 7: Neu cho 1 mol m6i chat: CaOCl,, KMn04, K2Cr207, Mn02 ISn luot

phan ling vdri luong du dung djch HCl dac, cha[t tao ra luong khi nhi^u

nhat la

A KMn04 B KjCrjO, C CaOa2 D

MnOz-(Trich De thi tuyen sinh DH khoi A) Hu&ng ddn gidi

PTPir xay ra:

CaOCU + 2HC1 > CaCU + CljT + H2O

Thi du 8: Co ba dung dich: amoni hidrocacbonat, natri aluminat, natri phenolat

va ba cha't long: ancol etylic, benzen, anilin dung trong sau 6'ng nghidm ri^ng biet Ne'u chi dung m6t thud'c thiJ duy nha't la dung dich HCl thi nhan biet duoc t6'i da bao nhieu 6'ng nghiem? ,

A 5 B.6 C 3 D 4

(Trich De thi tuyen sinh DH, kh6i_Al_

39

Hu&ng ddn gidi

- Trich cac m i u thu vao 6'ng nghiSm

- Cho tijf tiir dung djch HCl vao cic mSu thif:

+ MSu nao tao ra khi bay Itn => m3u chura amoni hidrocacbonat NH4HCO3:

+ MSu tao ra chat long kh6ng tan => mSu chiia ancol etylic Q H j O H :

HCl + C3H5OH — ^ C2H5CI + H2O

khdng tan

+ MSu tao ra 2 Idrp chSft long kh6ng tr6n ISn vao nhau => mSu chira benzen C^Hf,:

HCl + QHe • Kh6ng tac dung

+ MSu tao ra dung dich ddng nha't =:> mSu chiia anilin CsHjNHz:

HCl + C^H^NH, > C 6 H 5 N H 3 C I (Tan)

DAp dn dung la B

Thi du 9: Di loai bo A l , Fe, CuO ra khoi h6n hop g6m A g , A l , Fe va CuO, c6

th^ dung lucmg d u dung djch nao sau day?

A Dung djch Fe(N03)3 B Dung dich H C l

C Dung djch HNO3 D Dung djch NaOH

(Trich detuyen sink Cao ddng khoi A) Hu&ng ddn gidi

V i A l , Fe, CuO d i u phan ling vdri HCl (dd), con A g khdng phan ihig vdi H Q

=> CO th^ diing dung djch HCl (du)

Dap an dung la B

TM du 10: Trong phong thi nghiem khi di^u che' tir MnOj va dung djch H Q

dac, dun nong, d^ loai bo khi H Q ISn trong nguoi ta thucmg rira khi nay bang

A dung djch H2SO4 B dung djch NaOH

C dung djch A g N O j D dung djch N a Q

Hu&ng ddn gidi

Nguod ta dung dung djch NaCl v i :

- H Q tan nhi^u trong dung djch NaCl

- K h i a It tan trong dung djch N a Q

cau 2: Hian umg cua cSp cha't nao dudri day khong th^ sijf dung d^ di6u chd' cac

mu6'i sat (III)?

Fe + L 2Fe + SBr,

C a u 3: Khi didu ch6 CI bang cdch cho KMn04 tac dung vdri dung djch H Q dac thi H Q

A vira la cha't khiJr, vtra la cha't tao m6i truomg

B la chat khijr

C. la cha't oxi hoa

D vira la cha't oxi hod, vCra Ik chSft tao m6i truomg

C&u 4: Phong thi nghidm bi 6 nhidm lirong nho khf C I , Phuong phap t6't nha't dung

di loai bo khf d6c nay la

A phun dung dich KBr B Phun dung djch N a O H

C phun dung dich CaCOH), D di hd lo dung dung djch N H , dSc

Hu&ng ddn gidi

Di loai bo lirgng nho khf Clj, phuong phap t6't nha't 1^ dting khf NH3 (khi NHj

duoc sinh ra bang each d^ ha lo dung dung dich NH3 dac)

3CU + 8NH3 ^ N , + 6 N H 4 a Dap an dung la D

Cau 5: Khi diiu chd' khf CK trong phong thi nghifim bang each oxi hoa axit HCl

khf clo thu duoc thucmg c6 l l n H C l Di loai bo khf H C l trong khf diiu chi duoc

c&n dSn h6n hop khi nay qua

A dung dich NaCl B nirdc

C dung dich AgNOj D dung dich NaOH

Hu&ng ddn gidi

Di loai bo H Q nguofi ta dSn h6n hop H C l , Q , qua dung dich NaQ V i dung

4 djch NaQ ha'p thu HCl, con CI2 tan v& ft trong dung djch NaCl

Dap an diing la A

Cau 6: Co eac hoa chat: K ^ C r A - H Q , KMn04, MnO,, NaCl, HCIO, H^SO,,

KCIO3 Nhihig hoa chat duoc sir dung d^ didu ch€ CI2 trong phong thf nghiem la

PTHH eac phan ung didu ehe CU trong PTN:

16HC1 + 2KMn04 ^ 2KCI + IMnCXj + 5CI2 + SHjO

Dang 4: Xdc dinh chat phdn vcng, phuong trinh hod hoc

vd chuoiphdn itng cua cdc halogen vd hop chat

1 L i thuyet v^n dung va phuong phap giai:

- Xem phdn If thuyfi't ve nhom halogen

- M6t s6' chu y:

+ Cac don chat halogen (F,, CI, Br,, I,) d^u c6 tfnh oxi hoa manh

+ Cac axit halogen hidric (HCl, HBr, HI) d^u c6 tfnh khif (tdc dung v6i eac

chat oxi hoa manh) va c6 tfnh oxi hoa (tac dung vdi kim loai)

+ Axit flohidric HF la axit yfi'u, c6 tfnh chat dac biet (an mon thuy tinh):

4HF + SiOz - > SiF4 + 2H2O

+ KhfCO, tacdungvorinude Javen, eloruav6i:

NaClO + CO2 + H2O - > HQO + NaHCOj

2CaOCl, + CO, + H2O CaCOj + CaClj + 2HC10 + FTHH: 2FeCl2 + a , - > 2FeCl3

2FeCl3 + Fe - > 3FeCl2 ^ ,

2 Cac thi du minh hoa:

Thi du 1: Cho phirong trinh hoa hoc (vdi a, b, c, d la cac h& s6):

aFeS04 + bCl2 -> cFe2 (SO4 )3 + dFeCl,

=>a:e = 6:2 = 3 : l Dap an diing la D

Thidu 2: Hay cho bid't, phan ling nao sau day HCl dong vai tro la cha^t oxi hoa?

Trong eac phan ling hoa hoc kim loai chi the' hifen tfnh khijf ntn khi tac dung vod

kim loai axit HCl dong vai tro la clia't oxi hoa Tfnh oxi hoa ciia HCl do thanh

Th( du 3: K h i nao sau day khong b | o x i h o i bofi nu6c gia-ven?

Chu y; - T u y vay, C O , vSn phan ling duoc vdi nude Giaven (khdng phai phan ling

oxi hoa - khiJf): C O 2 + H 2 O + NaClO - > HCIO + N a H C O j

- Cac k h i b i o x i hoa boi nude Javen:

SO2 + NaClO + H 2 O NaCl + H2SO4

H 2 S + 4NaC10 - > H2SO4 + 4NaCl

16Ha + 2 K M n 0 4 > 2KCI + 2 M n a 2 + SCU + SHjO

S6' phan ung trong d6 H C l th^ h\tx\h oxi hoa la

(Trich Delhi tuyen sink DH - CD khoi A) Hu&ng ddn gidi

Trong cac phan iJng, HQ thd' hidn tinh o x i hoa k h i n6 tac dung vdri k i m loai (tinh

oxi hoa ciia ion H*)- D o do trong cac phan ung v d i k i m loai, H C l t h ^ hidn tinh

Thidu 5: Cho cac chat: A l , AUO3, Al2(S04)3, Zn(OH)2, NaHS, K2SO3, (NH4)2C03

S6' chat d^u phan ihig duoc vdd dung dich HCl, dung dich N a O H la

*) D 6 1^ m6t s6' kim loai ( A l , Z n , ) :

2A1 + 6 H a > AICI3 + 3H2

2A1 + 2NaOH + 6H2O >• 2 N a [ A l ( O H ) 4 ] + 3H2

*) Cdc chat luong tinh: j ,

AI2O3 + 6 H a > 2Aia3 + 3H2O

AI2O3 + 2NaOH + 3H2O ^ 2Na[Al(OH)4] , , ^ Zn(OH)2 + 2 H a > Z n a 2 + 2H2O

Phat bi^u diing la :

A Tinh khix ciia CI" manh hon Br"

B Tinh oxi hoa ciia Brj manh hon ctia Q 2

C Tinh khu ciia Br" manh hcni ciia Fe"*

D Tinh oxi hoa ciia Gi manh hon ciia Fe'* "

(Trich De thi luyen sinh DH - CD khdi B) Hu&ng ddn gidi

T a c o :

• Tinh khir ciia Br" manh hon Q" (vi tinh khir F < Q" < Br" < T) Tinh oxi hoa 0 2 manh hon Br2 (vi tinh oxi hod ciia F2 > CI2 > Br2 > I2) Tinh khir ciia Fe'* manh hon Br" (dua vao phan ling thii nha't)

Tinh oxi hoa ciia Br2 manh hon Fe'* (dua vao phan iitig thuf nha't), tinh oxi hoa

^"a CI2 manh hem ciia Br2 n6n tinh oxi hoa ciia CI2 manh hem Fe'*

E>ap an diing la D

I l l iHMl WW giui nnann B I nuu nt^v, z - i num i uan

Thi du 7: Day g6m c&c chat d^u tac dung diroc vdfi dung dich H Q loang 1^

A AgNOj, (NH4)3C03, CuS B Mg(HC03)2, HCOONa, CuO

C FeS BaS04, KOH, D KNO,, CaCOj, Fe(OH)3

(Trich De thi tuyen sink Dai hoc khd'i A) Hu&ng ddn gidi

Xet cac phuong an: • ^ : • , ;•>••

A Loai VI CuS

B. Thoa man:

MgCHCOj), + 2HC1 > MgQj + 2C02t + 2K^O

HCOONa + HCl > HCOOH + NaQ

CuO + 2HC1 > CuCU + H2O

C Loai vi BaS04

D Loai VI KNO3

Dap an dung la B

Thi du 8: Cho cac phan utig sau:

(a) 4HC1 + PbO, > PbQ, + CI2 + 2H2O

(b) HCl + NH4HCO3 > NH4CI + CO, + H2O

(c) 2HC1 + 2HNO3 > 2NO, + 0 2 + 2H2O

b) H Q + NH4HCO3 > NH4CI + CO2 + H2O

c) 2HC1 + 2HNO3 > 2NO2 + + 2H2O

Chat khiJf

d) 2HC1 + Zn > Z n a 2 + H2 ^ ' ^'

Co 2 phan umg trong do H Q the' hien ti'nh khir

Dap an dung la D

Thi du 9: Co cac thi nghidm sau:

(I) Nhung thanh sSt vao dung dich H2SO4 loang, ngu6i

(II) Sue khi SO, vao nu6c brom

(III) Sue khi CO, vao nirdc Gia - ven

(IV) Nhiing la nh6m v^o dung djch H,S04 dac, ngu6i

S6 thi nghiem xay ra phan ting hoa hoc la

(III) : CO2 + H,0 + NaQO > HCIO + NaHCOj

Co 3 phan ling hoa hoc xay ra

Chuj: Halogen (F,, CI,, BTJ, L , At2) kh6ng tac dung true tie'p voi O2

3 Cac bal tap tu luyen:

CSu 1: Truorng hop khong xay ra phan ling hoa hoc la

A CI, + 2NaOH > NaCl + NaQO + H2O

KttJtuat mm gidt nhanh BTHoa hoc, tap 2 - Cu Thanh Tonn

B K h d n g xay ra V i FeS tan trong dung djch H Q :

FeS + 2Ha > FeCl, + H^S

c Diing

d D i i n g

Dap dn dung la B ;^

cau 2: Cho day cac chat: CsHjOH (phenol), C6H5NH2 (anilin), HjNCHjCOOH,

C H j C H j C O O H , CH3CH2CH2NH2 S6 chat trong day tac dung diroc vdi dung

Cac cap cha't tan hoan toan trong dung dich H Q nong la:

Cu + 2FeCl3 > 2 F e C l 2+CUCI2

b) Sn + 2HC1 >.SnCl2 + H2

Z n + 2HC1 > Z n a 2 + H2

d) Fe2 ( 5 0 4) 3 + ^" ^ CuSO^ + 2FeS04

Co 3 cap chA thoa man

Dap an diing la A

C&u 4: H6n hop chtia d6ng thoi x mol m6i chat Fe304, Cu, A l , N a Q c6 th^ h6a tan

hoan toan trong luong d u dung djch nko sau day?

A dung dich NH3 B dung dich N a O H

C dung djch H C l D dung djch A g N O , $

Hu&ng ddn gidi

H6n hop Fe304, Cu, A l , N a Q c6 th^ tan trong dung djch H Q dir:

Fe304 + 8HC1->2FeCl3 + FeClj + 4H2O

Cu + 2FeCl3 ^ C u C l 2 + 2 F e a 2 > f ; : > l ' ; ' /

X 2x ^ • 2A1 + 6HC1 ^ 2AICI3 + 3H2 • ; J NaCl + H 2 0 ( d d H C l ) d d N a C l

Ddp dn diing la C ,

cau 5: Vi6't va khac hinh \tn kinh, thuy tinh dua vao phan litig

A Si02vaHF B SiOz vk dung djch N a O H

C SiO: va H I D Si02, Na2 CO3 va CaCO,

0 a 2 + 2 K I - > l 2 + 2 K C l 8) 6Kl + K 2 C r 2 0 7 + 7 H 2 S 0 4 - > 3 l 2 + 4 K 2 S 0 4 + C r 2 ( S 0 4 ) 3 + 7 H 2 0

Cau 7: Cho clo Un lircrt vao: dung dich NaOH, dung djch Ca(OH)2 dSc, HjS, NH,

S6 tru£mg hop clo vira th^ hifin tinh oxi hod vira th^ hidn tinh khii Ik

Dap &n diing Ik D

C M i - * Qorua v6i CaOCL

-1

ClCaOCl

Cau 8: Cho ba chat: khi Q j , b6t Fe, dung djch H Q

Viet PTHH ciia cac phan ling bid'u dien sad6 sau:

da v6i va mu6'i an

Hu&ng ddn gidi M V''

CaC03 •^^•"^g^"^ ) CaO + CO2 ' • CaO + H20^Ca(OH)2

2Naa + 2H.O , '^^'^ ^ ) H , t + CI, t + 2NaOH ' • '•' > ^

CI2 + Ca(OH)2 -> CaOQj + H2O

Dang 5: Mot so cdu hoi It thuye't ve halogen

1 L i thuye't van dung va phirong phap giai:

- Xem phSn l i thuyd't v^ nhom halogen » '

- M6t s6' n6i dung cin chii y:

+ Trong cac phan ung hoa hoc, F^ chi thfi' hifin tmh oxi hoa Trong moi truomg hg(p chat nguydn t6' flo chi c6 s6' oxi hoa duy nha't la - 1

+ Cac don chat d^u c6 tinh oxi hoa manh, tinh oxi hoa giam din tir F2 dd'n Ij

+ Cac nguydn t6' halogen khac (CI, Br, I) ngo^i s6' oxi hoa - 1 , c6n c6 kha nSng th^ hidn cac s6' oxi hoa +1, +3, +5, +7

+ Axit HF la axit ye'u, cac axit H Q , HBr, HI \h cac axit manh v^ tinh axit tang d ^

+ Tinh khijr cac hidro halogenua tang din HF < H Q < HBr < HI

+ Tinh khir ciia cac ion halogenua tang d^n theo tii tu: F , Q", Br", I "

+ Cac dung djch chiia cac ion halogenua (trCf florua) d i u phan ihig diroc vdi AgNOj tao thanh cac kd't tiia c6 mau sdc khdc nhau ^

2 Cac thi du minh hoa:

Thidu 1: Cho cac phat bid'u sau:

(a) Trong cac phan ung hoa hoc, flo chi th^ hifin tinh oxi hoa

(b) Axit flohidric la axit yfi'u ^i'

(c) Dung djch NaF loang duoc dung lam thu6c chd'ng sau rang

W)Trong hop chat, cac halogen (F, Q, Br, I) d^u c6 s6' oxi h6a: - 1 , + 1 , +3, +5

Hu&ng ddn gidi

X6t cac phat bie'u:

(a) Diing v i F, la chat o x i hoa manh nha't

(b) D i i n g VI lien ke't H - F rat b^n vutig nen kho phan l i ra H*:

H F i r i + F"

(c) Diing (dung dich NaF loang lam thu6c chd'ng sau rang)

(d) Sai V I trong ta't ca cdc hop chat, flo chi c6 s6' o x i hoa duy nha't la - 1

(e) D i i n g , tinh khir F < Q " < Br" < I " (vi d6 am dien va d6 b^n giam d^n)

=> Co 4 phat bie'u diing

Dap an diing la D

Thi du 2: Phat bie'u nao sau day diing?

A lot c6 ban kinh nguyen tir 16n hom brom

B A x i t H B r c6 tinh axit ye'u hon axit H C l

C Flo CO ti'nh o x i hoa ye'u hon clo

D Dung djch NaF phan ung vdi dung djch A g N O , sinh ra A g F ke't tiia

(Trich detuyen sinh Cao dang khoiA) Hu&ng ddn gidi

- Br, I e V I I A , vi Z , > Zg^ r, > x^^

- V I rgr > rc, => dH_Br > d^.Q => axit HBr manh hon axit H C l

- Fj la chat o x i hoa manh nha't nen tinh oxi hoa F j >

- NaF + A g N O j - > khdng xay ra vi A g F tan

=> Phat bie'u dung la A

Dap an diing la A

Thi du 3: Phat bie'u nao sau day khong diing?

A Dung djch H F hoa tan dugc SiO,

B Trong cac hop chat, ngoai s6' o x i hoa - 1 , flo va clo con c6 cac s6' o x i hoa

+ l , + 3 , +5, +7

C Flo CO tinh o x i hoa manh hem clo

D Mu6'i A g l kh6ng tan trong nu6c, muoi A g F tan trong nirdrc

(Trich detuyen sinh Cao dang • KhoiA) Hu&ng ddn gidi

X6t cdc phat bie'u:

A D i i n g : 4 H F + SiOj SiF4 + 2H2O

B Sai, VI nguyen t6' flo, trong hop cha't chi c6 s6' cxi hoa duy nha't 1^-1

C D i i n g : F j + 2 N a C l ( n / c ) — ^ ^ Q j + 2 N a F

D D i i n g : Trong cac mu6'i bac halogenua A g X , chi c6 A g F tan t6't trong nude

con cac bac halogenua khac ( A g C l , AgBr, A g l ) d^u kh6ng tan

=> Phat bi^u B khdng diing

Dap an diing la B

"ffti du 4- Phat bi^u nao sau day la sai?

^ Ban kinh nguyen tiir cua clo Idn hon ban ki'nh nguyen tiJr ctia flo

g E)6 am dien ciia brom Ion hon d6 am dien c i a iot

C Tinh axit ciia H F manh hon tinh axit ciia H C l t ,

-D Tinh khiJ ciia ion Br" Ion hon tinh khif c i a ion C P

(Trich detuyen sinh Dai hoc, khoi A) Hu&ng ddn gidi

Tinh axit trong day halogenhidric: HF < H C l < H B r < H I (Giai thich dira vao d6 ben lien ke't H - X )

=> Phat bi^u C sai

Dap an diing la C

Thidu 5: Phat bi^u nao sau day khdng diing?

A A x i t H F CO tinh axit ye'u hon axit H I

B A x i t H2CO3 CO tinh axit manh hon axit HCIO

C A x i t HCIO4 CO tinh oxi manh hon axit HCIO

D H F CO nhiet d6 s6i cao hon H I

Hu&ng ddn gidi

Nhan xet:

- Tinh axit: H F < H Q < H B r < H I

- Tinh axit H3CO3 > H Q O : H2CO3+NaC10-^HC10 + NaHC03

- Tinh o x i hod HCIO4 < H Q O : + HCIO4 rat b^n, ton tai dang nguyen cha't

+ HCIO rat kem ben, chi t6n tai trong dung dich rd't loang

- t ° ( H F ) > t " ( H I ) V I H F CO lien ke't hidro lien phan tir ben hon nhi^u (lien ke't H

F phan cue hon lien ke't H -1 )

Dap an diing la C

52

Thidu 6: Phat bie'u nao sau day la dung?

A Cho tinh th^ N a l vao dung dich H2SO4 dSc, dun n6ng thu duoc H I

B- Sue k h i CI2 vao dung djch NaOH loang, nong thu duoc nu6c Gia-ven

C C6ng thijc oxit cao nha't ciia flo la F j O ,

— - ^ ^ j j u o c da CO ca'u triic mang tinh the' phan tii

Hu&ng ddn gidi

PTHH: 2 N a I + 2H2SO4 -> Na2S04 +12 + SO2 + 2H2O

=^ Kh6ng thu duoc H I

^ H : 3CI2 + 6NaOH — ^ 5NaCl + NaClOj + 3H2O

^ Khdng thu duoc nudic Javen

- Nguyen t6 flo khdng tao diroc oxit cao nha't XjO, nhir cdc halogen khdc

- Nirdc da c6 ca'u true mang tinh th^ phan til

=> Phat bi^u dung la D

Dip an diing la D

Chu y: Cac oxit ciia flo c6 c6ng thiic chung FjOn (n = 1, 2, 3 va 4)

r f

C BAI TAP TONG HOP vfi HALOGEN

C&u 1: Dung djch HQ va dung djch CH3COOH c6 cung n6ng d6 mol/1, pH ciia hai

dung djch tuofng umg la x va y Quan he giiJa x va y la (gia thie't, cii 100 phan tu

CH3COOH thi CO 1 phan tijr didn li)

Cau 2: Clo hoa PVC thu diroc m6t polime chiia 63,96% clo v^ kh6'i luong, trung

binh 1 phan tir clo phan ihig v6i k mat xich trong mach PVC

Gia tri ciia k la

CSu 4: Khi difin phan dung dich mu6i an bao hoa d^ san xu^t xiit, ngucri ta thu duoc 560 lit khi clo b Aiin kiSn tidu chu£n Tinh khd'i luong mu6l an chita 98%

NaCl da dung Ai didn phan Bie't hidu sua't ciia qua trinh difn phan 1^ 1(X)%

Hu&ng ddn gidi

S6 mol 0 2 thu duoc: nci2 = ~ r = 25 (mol)

Phuong trinh difin phan:

2Naa + 2H2O > H, t +2NaOH + CUt (1)

Theo (1): nN^cicdn = 25 2 = 50 (mol) Kh6'i luong NaQ cSn diing: m N , c i = 50.58,5 = 2925 (g) = 2,925 (kg)

Khd'i luong muC»i an chura 98% NaCl c^n la'y Ik

Cau 3: Tinh the tich khi clo thu duoc 6 di^u kidn tidu chu^n khi:

a) cho 7,3 g HQ tac dung he't \di MnOj

b) cho 7,3 g HCl tac dung he't vdi KMnO* »

cau 5: Cha't nao sau day khbng th^ dung d^ l^m kh6 khi hidro clorua?

C Axit sunfuric dam dac D CaQj khan

Hu&ng ddn gidi

- P2O5, axit sunfuric dam dac va CaClj khan d^u c6 kha nang hut im, kh6ng phan

utig vori HCl nen duoc dung de' lam kh6 khi HQ

- NaOH ran c6 tinh hiit im, nhung lai phan ung v6i HQ ntn kh6ng duoc dung di

kh6 khi HCl

£>^panB

6: Phan umg nao sau day chiing to HQ c6 tinh khir?

A 4HC1 + MnOj MnO + CI2 + 2H2O

B- 2HC1 + Mg(OH)2 - > M g a 2 + 2H2O

C 2HC1 + CuO C u a 2 + H2O

2HC1 + Zn — ZnQ, + H2

55

Hudmg ddn gidi

- Phan ling 4 H a + MnOz > MnQj + 0 2 + IHjO, nguyfin ttf O trong HC]

cho electron: 2Cl' > + 2e, nfin HCl trong phan ling n^y c6 tinh khif

- d phan ling B va phan ihig C, s6 oxi hoa cua H va Q kh6ng thay ddi ntn HCl o

hai phan ling n^y kh6ng th^ hifn ti'nh oxi hoa hay ti'nh khir ,,

+1 0

- O phan ling D, 2 H (HQ) + 2 le > Hj ntn H Q th^ hien tmh oxi h6a

Dap in A

C&u 7: Muefi an bj 15n cdc tap cMt Ik Na2S04, MgQz, Caa2 CaS04 Hay tnnh

b^y phirong phap hoa hoc loai bo cac tap chat Viet PTHH cua cac phan irng

\ky ra

Hudng ddn gidi

- H6a tan mu6'i v^o nirdc r6i loc se loai bo duoc CaS04 it tan (nuorc loc v5n chua

m6t lucmg nho CaS04)

- Cho v^o nude loc m6t luomg du dung dich BaQj:

BaQz + CaS04 - » BaS04 i + C a a 2

BaQj + Na2S04 BaS04 i + 2 N a a

Loc bo ke't tiia BaS04, nude loc chiia C a a 2 , MgClj, NaCl va BaQj

d« Them v^o nu6c loc m6t luong dung djch NajCOj la'y du:

NajCOj + CaQz -> CaCOj i + 2Naa

NazCOj + MgClj -> M g C O j i + 2Naa

NajCOj + BaQj BaCOj i + 2Naa

- Loc bo ke't tiia, nude loc chi chiia NaCl NajCOj du Cho nudrc loc tac dung

v<M dung dich HCl du: NajCOj + 2HC1 ^ 2NaCl + C O j t + HjO

Dung djch con lai chiia NaQ va HCl du, c6 can dung dich thi HCl du bay hoi

bet, thu duoc NaQ tinh khie^t

C&u 8: Mud'i an khdng nhutig c6 tSm quan trong trong dcri s^ng hang ngay ciia con

nguiri con la nguyen lieu de' san xua't natri hidroxit, clo, axit clohidric

Vie't PTHH ciia cac phan umg diing de' san xuit cac cha't tren

Khi HCl tan rat nhi^u trong nude, vi vay phai dung H2SO4 dac va mu6i b tranj

thai tinh th^ de' ban che' hidro clorua tao thanh tan trong nude

Cau 10: Cho h6n hop A g6m Cu va Mg vao dung djch HCl du thu duoc 5,6 lit khi

(dktc) kh6ng mau va m6t chat ran khdng tan B

Dung dung dich H2SO4 dac, nong de' hoa tan hoan toan chat r l n B thu duoc 2,24 h't khi SO2 (dktc)

a) Viet PTHH ciia cac phan ling xay ra

b) Tinh kh6'i luong h6n hop A ban ddu

Hu&ng ddn gidi

a) Cic phan umg

Mg + 2 H a - > M g Q j + H j t (1) Cha't ran kh6ng tan B la Cu

C&u 9: De' di^u che' khi hidro clorua, ngudi ta cho mudi NaQ tac dung vdi axit

H2SO4 dac, nong Viet PTHH ciia cac phan dug xay ra va giai thich vi sao phai

dung mud'i tinh th^ va axit dam dac

b) Theo (1): n^g = " H J = = ^,25 (mol); mM^ = 24.0,25 = 6 (g)

Z z , 4

2 24

Theo (2): = njoj = T T — = 0,1 (mol); nio, = 64.0,1 = 6,4 (g)

Khd'i luong h6n hop A la: m ^^A = 6 + 6,4 = 12,4 (g)

C&u 11: Brom bj I3n tap cha't la clo Di thu duoc brom cin \km each nao sau day?

A DSn h6n hop di qua dung dich H2SO4 loang

B D i n h6n hop di qua nu6c

C DSn h6n hop di qua dung djch NaBr

D DSn h6n hop di qua dung djch Nal

Hu&ng ddn gidi

Brom bj iSn tap chat 1^ clo, de thu duoc brom c^n dkn h6n hop di qua dung djch

NaBr, toan b6 tap cha't CU se phan tag vdri NaBr :

+ 2NaBr > 2NaCl + Brj Dap an C

C&u 12: Day axit nao sau day sip xe'p dung theo thvc tu giam din tinh axit?

A H I > HBr > HCl > HF B HP > HCl > HBr > H I

C HCl > HBr > H I > HF D HCl > HBr > HF > H I

Hu&ng ddn gidi

B^n kinh nguyen tir cac halogen (X) duoc sap xe'p giam d^n theo day: I >

CI > F, nen d6 dai lien ke't giSa cac nguyen tir X vdd nguyen tu H cung giam d^n theo day: H I , HBr, HCl, HF (1), nen kha nang phan l i ra ion H* ciia cac HX

cung giam din theo day (1), tiic tinh axit giam din theo day (1)

Dap an dung la A

C&u 13: Day ion nao sau day sSp xd'p diing theo thir tu giam din tinh khijr?

A F" > C r > Br~ > r B I " > Br" > CP > F"

c B r > r > c r > F " D a ~ > F - > B r - > r

Hu&ng ddn gidi

Tmh oxi hoa ciia nguydn tir cang manh thi tinh khir ciia ion am ciia no cang yd'u

Tinh oxi hoa ciia F > Q > Br > I , ndn tinh khijf ciia F > Br~ > Q " > F~

Dap an diing la B

C&u 14: Vi sao ngucri ta c6 th^ didu ch6' Ch Brj, bang each cho h6n hop HjSO^

dac va M n 0 2 tac dung vdri mu6'i clorua, bromua, iotua nhimg kh6ng thi ap dung

phuong phap nay d^ di^u ch6 F,? Bang each nao c6 the' di^u chd' dugc Fj? Viet

PTHH ciia cac phan ling

Hu&ng ddn gidi

Ngucd ta c6 th^ dilu ch^ CU, Brj, I , bang each cho h6n hop H 2 S O 4 dac va MnO,

tac dung vori mu6'i clorua, bromua, iotua Cac san ph^m trung gian 1^ HQ, HBr,

HI bi h6n hop (MnOj + H2SO4) oxi hoa thanh Q j , Brj, I2

Cac PTHH cua phan ling:

NaCl + H2SO4 — ^ NaHS04 + HCl

K h 6 n g the' ap dung phuong phap trfen d^ di^u ch^ F2 vi h6n hop oxi h6a

(MnO, + H2SO4) khdng dii manh di oxi hoa HF thanh F j

Cach duy nha't di di^u che' F21^ difin phan h6n hop KF tan trong HF long khan

(kh6ng C O mat HjO) Dung dong didn m6t chi^u 8 - 12 v6n ; cucmg d6 4000

-6000 ampe; binh didn phan c6 eatot lam bang thep dac biet hoac bang d6ng va

anot lam bang than chi (graphit)

dcatot: 2H" + 2 e ^ H 2

d anot: 2F ^ F, + 2e

Cau 15: Bang phuong phap hoa hoc nao c6 th^:

a) Xac djnh duoc c6 khi clo iSn trong khi hidro clorua?

b) Thu duoc khi clo tCr h6n hop khi b cau a?

c) Thu khi hidro clorua tiJr h6n hop khi a cau a?

Viet PTHH ciia cac phan ung xay ra

\ ddn gidi

Cdch 1: Cho h6n hop khi di qua dung djch NaBr hoac dung dich NaT, CI, se oxi

hoa NaBr hoac Nal thanh Br, hoac I , lam cho dung djch khdng mau ban diu

chuyen thanh mau vang hoac mau nau

a, + 2NaBr -> 2NaCl + Br2 (dung djch c6 mau vang) hoac + 2NaI -> 2NaCl + I2 (dung dich c6 mau vang nau)

Cdch 2: Co thi nhan bid't h6n hop khi bang gia'y quy tim ^m Luc d^u quy tim

chuye'n thanh mau do, do h6n hop khi c6 HQ Sau d6 mau do bie'n mat do trong

h6n hop CO khi Ch Khi 0 2 tac dung vdi H2O sinh ra HCIO c6 tinh oxi hoa rat

manh, lam mat mau do

CI2 + H2O ^ HCl + HCIO

b) Cho h6n hop khi trdn (HCl va CU) tac dung vdi chat oxi hoa manh nhu MnO,, dung dich KMn04 HCl bj oxi hoa thanh CI2 kit qua thu duoc chat khi duy

a) Cach phan biet mu6'i dung trong m6i lo bang phuong phap hoa hoc

b) Tir nhOng mud'i da cho di^u chd' cac halogen tuong ihig \h cac hidro

halogenua tuong ling

Hu&ng ddn gidi

a) Cdch 1: La'y m6t it cha't trong m6i lo dem hoa tan vao nu6c duoc cac dung djch

ri^ng biet, sau do lin luot cho AgNOj v^o cac dung dich do se nhan ra duac cac

dung djch do xua't hl6n cac hidn tuong khac nhau:

KF + AgNOj > Kh6ng phan ihig '

Ki thu4t tn6i gidi nhanh BT Hod hgc, tap 2-Cu Thanh Toan

- Nhutig dung dich con lai, dung djch nao tac dung duoc voi Clj tao ra dung

dich C O m^u vang nau (mau ciia Btj tan trong nu6c), do la dung dich KBr

+ 2KBr -> 2KC\ Br,

- Hai dung dich con lai la K F va KCl : Cho tac dung vdi dung dich AgNOj,

dung djch nao tao ra k6t tiia trlng, do la dung dich K C l

K Q + A g N O j ^ AgCl i + KNO3

- Dung djch con lai la K F , kh6ng phan utig vdri A g N O j

b) Dieu che halogen tUcmg iTng tiJt mud'i da cho :

- Diiu ch6 F,: D'l&n phan K F tan trong chat long H F khan thu duoc F , or an6t

- D i l u che' Clf Didn phan dung djch K Q trong nu6c, c6 mang ngan

2Ka + 2H2O _ J P ^ H , t + CI21 + 2 K O H

Phan umg t6ng cua (1), (2), (3) la:

2KBr + M n O , + 2H2SO4 K.SO, + MnS04+ Br2+ 2H2O (4)

- Di^u cha' I2 tuong tu di^u che Br2 va c6 phan ling t6ng la:

2 K I + M n O , + 2H2SO4 — ^ K2SO4 + MnS04+ I2+ 2H2O

Dieu chehidro halogen tit cac muoi tuang itng:

- Didu cha' H F : K F + H2SO4 — ^ KHSO4 + H F T

- D i l u cha' H C l : K Q + H2SO4 — ^ KHSO4 + HCl t

- Di^u cha' HBr: Dian phan dung djch KBr c6 mang ngSn (hoac tac dung

vdri dung djch KBr, hoSc cho mu6'i KBr tac dung vdri h6n hop Mn02 va H2SO4

dac) duoc Br,, sau do cho Br, tac dung vdri H j 6 nhiat d6 cao diroc HBr

2KBr + 2H2O — ^ E ^ l ^ H2 + Br, + 2 K O H

H2 + Br, — ^ 2HBr

Di^u che' H I : tuong tir di^u che' HBr b Irtn hoSc tir I , ta dieu che' H I bang

each dung khi H,S khu I ,

Cka 1 8 : M6t h6n hop Y g6m A l va Fe Cho 22 gam Y tac dung vdri 2 lit dung djch

H Q 0,3M thu diroc V lit khi H , (dktc) ^

a Chung minh rang h6n hop Y kh6ng tan het Tinh Vj^^ (dktc)

b Cho 22 gam Y tac dung vdri clo du thu duoc mj gam mu6'i Na'u cho 22 gam

Y tac dung v6i iot du thu duoc m2 gam mu6'i Biet m2 - m, = 139,3 gam Tinh

khd'i luong m6i k i m loai trong 22 gam Y

V i kim loai het nan: 3x + 2y < 0,6 ( I ) "it t

Tac6: 0 ^ 4 ,= x + y - > ^ < x + y < ^ ^ 0,392 < x + y < 0,815

56 27 0,784 < 2x + 2y < 3x + 2y (II) TiJr (I) va (II) ta tha'y di^u gia sir sai Vay axit phan ufng hat

- > m 2 = 408x + 310y (2)

Theo hM ra ta c6; 27x + 56y = 22

m j - m , = 139,3 ^ 2 7 4 , 5 x + 147,5y= 139,3 ' i» \

- > X = 0,4 mol va y = 0,2 mol. ; ^ u T,r

Vay ITIAI = 10,8 gam va m p = 11,2 gam i ^ • » ' » "

Cau 19: Cho h6n hop A g6m c6 NaCl, NaBr \h Nal Hoa tan 5,76 gam A vko nu6^

r6i cho tac dung vdi lirong du dung dich nude brom, sau phan ufng hoan tokn thu

ducrc 5,29 gam mu6'i khan Mat khac, khi hoa tan 5,76 gam A vao nuoc r6i cho

m6t luomg khi clo di qua, sau phan ting c6 can thu diroc 3,955 gam mu6'i khan

trong d6 c6 chiia 0,05 mol NaCl

^ 1 Viet cac PTHH ciia cac phan irng xay ra

2 Tinh % kh6'i luong cac chat trong h6n hop A

Hu&ng dan gidi

1 Cac PTHH xay ra:

2NaI + Br, > 2NaBr + 1 , (1)

2NaI + a, > 2NaCl + I , (2)

2NaBr + CI, > 2NaCl + Br, (3)

2 Goi a, b, c Idn luot la s6' mol ciia NaQ, NaBr, Nal, theo d^ ta c6:

* Xet trufirng hofp 1:

Nal du => NaBr chua phan ting

Goi X la s6' mol Nal phan ling Theo ptpu (1) va (2) vk theo b^i ra ta c6:

58,5(a + X) + 103b + 150(c x) = 3,955 (***)

a + x = 0,05 (****)

Ke't hop (*), (**), (***), (****) (loai vi c - X < 0)

* Xet t r u ^ g hflfp 2:

NaBr phan ung 1 phSn => Nal phan irng he't

Goi y la s6' mol NaBr phan ufng Theo (1), (2), (3) v^ theo b^i ra ta c6:

58,5(a + c + y) + 103(b - y) = 3,955 (*****)

a + c + y = 0,05 (******)

Ke't hop (*), (**), (*****), (******) ta c6:

58,5a + 103b + 150c = 5,76 58,5a+ 103{b + c) = 5,29

vao dung djch nay, khua'y ki cho dd'n khi phan ling hoan toan tha'y kh6'i luong

kim loai tang 19,2 gam Nd'u sue khi Clj dir vao dung djch X cho de'n khi cac phan utig hoan toan sau do c6 can dung djch, thu duoc 33,625 gam mu6'i khan

Viet cac PTPU" xay ra va ti'nh thanh ph^n % kh6'i luong ciia m6i chat trong h6n hopdSu

Hu&ng ddn gidi

Theo bai ra: n^gNOj =0,5.1,7 = 0,85(mol)

Goi X, y, z \in luot la s6' mol MgQ,, NaBr va Nal trong dung djch X

* X tac dung vol dung djch AgNOj:

MgCI, + 2AgN03-> 2Agai + MgCNOj),

SQj +12 + 6H2O ^ 1OHCI + 2HIO3

^U6'i thu diroc g6m: (y + z) mol NaQ; x mol MgQj

=^ 58,5 (y + z) + 95x = 33,625 (3)

63

Cau 21: Sau khi dun nong 23,7 gam KMn04thu duoc 22,74 gam h6n hop ch&i ran

Cho h6n hop chat ran trfin tac dung hoan toan vdi dung djch axit H Q 36,5%

(d = 1,18 g/ml) dun nong

1) Viet PTHH cua cac phan umg xay ra

2) Tinh th^ tfch khi CI, thu duoc (d dktc)

3) Tinh the' ti'ch dung djch axit HCl cin diing

Hu&ng dan gidi

1 Cac phuong trinh phan ling xay ra: ,o

2 K M n 0 4 — > K2Mn04 + M n O j + O2 t

Chat ran sau phan ling g6m: K2Mn04, MnO, va KMn04 chua phan utig

Cho san ph£m tac dung vdi dung djch HCl c6 cac phan ung:

2KMn04 + 16HCI ^ 2KC1 + 2MnCU + 5 0 , + SHjO

Ap dung djnh luat bao toan nguyen t6:

" H C l = n K C i +2nMnci2 +2nci2 =0,15 + 2.0,15 + 2.0,315 = 1.08 mol

X , 1,08.36,5.100 ^,

vay V , „ „ , , i , , H O = ^ = 91,53(ml)

64

22: Hoa tan hoan toan h6n hc^ X g6m Fe va M g bang m6t luong vifa du dung

dich HCl 20%, thu duoc dung djch Y N6ng do cua FeCXj trong dung djch Y la

15 76% Tinh n6ng d6 ph^n tram cua MgCl2 trong dung djch Y

Hu&ng ddn gidi

Goi X va y I5n luot la s6' mol cua Fe va M g trong 1 mol h6n hop Phan ling: Fe + 2 H a ^ FeQj + H^ (1)

M g + 2 H a M g Q j + H2 (2) • i < , Theo (1, 2): n(Ha) = 2 mol va n(H2) = 1 mol

Suy ra: m (dung djch moi) = 56x + 24y - 2 + 36,5 2 100/20 = 56x + 24y + 363

95.0,5.100

r:>x = y = 0,5 -% = 11,79%

V

56.0,5 + 24.0,5 + 363

Cau 23: Nung 14,38 gam h6n hop KCIO3 va KMn04 in6t thori gian duoc h6n hop chat ran A va 1,344 lit (dktc) khi thoat ra Cho dung djch HCl dac, du vao A de'n

khi cac phan ung ke't thiic tha'y c6 3,36 lit khi (dktc) thoat ra (cho rang cac khi

tao ra d i u thoat he't khoi dung djch) Thanh ph^n % kh6'i luong ciia KMn04 trong h6n hop ban dSu la

A 35,6% B 65,9% C 76,8% D 56,8%

Hu&ng ddn gidi '

-Theo bai ra: =0,06 (mol); nci2 =0,15(mol) ,

Ta CO so do cac qua trinh xay ra: V

KCI

Mn02 KCIO3 KMn04

, (A)

£>at x, y l^n luot la s6' mol cua KCIO3, KMn04 trong h6n hop ban ddu

Theo bai ra ta c6: 122,5x + 158y = 14,38 (1) Theo djnh luat bao toan electron ta c6: 6x + 5y = 0,06.4 + 0,15.2 Tfr (1, 2) ta c6: x = 0,04; y = 0,06

C H U Y i N o f 2 : K T T H U A T G I A I NHANH CAC DANG BAi TAP VE N H 6 M O X I - Ll/U H U t N H

Tinh chat hoa hoc

Oxi (O2)

- K h i kh6ng mau, kh6ng miii-

- ft tan trong nir6c

* La phi k i m hoat d6ng c6 tinh oxi hoa manh

- Phan tur tuong doi bin

(Eo = o = 494kJ/mol)

O >2000''c 0 + 0

- Tac dung vdi hSu het kim

loai (trir A u , Pt) va hiu het

phi kim (trur halogen):

^ 200°C 4Ag H- O >

2 A g , 0

2Cu + O , — ^ 2CuO 2CO + O ^ 2CO,

2H, + O , 2 H , 0

Ozon (O3)

- Khi mau xanh nhat, CO mui dSc trung

- O 3 tan gap I 6 I & O 2

* Co tinh oxi hoa rat manh va rnanh hon

- Rat k6m b^n:

O 3 >02 + 0

- Oxi hoa Mu het

cac kim loai (trijf A u , Pt) va phi k i m : 2Ag + O 3

- Tan v6 han trong nu6c

* Viifa CO tinh oxi hoa (manh) vufa c6 tinh k h i

- K ^ m b ^ n :

XI

2 H 2 0 2

2 H 2 0 + 0 , -Tac dung v6i chat

+ 8 H , 0

H,o,+ a

O, + 2HC1 Che' - Chung ca't phan doan khong khi long

- 6CO, + 6 H , 0

- 3 0 , uv 4. 2O3

as.xt C,HnO, + 6 0

- L a tinh thd' mau vang,

kh6ng tan trong nirdc, tan

trong dung m 6 i hiru ca

- La chaft k h i khdng mau, m u i tning

thd'i, d6c, ft tan trong nude

H2S + 4 0 2 + 4H2O ^ SHO + H2SO4 H2S + 3H2S04(j) > 4SO2 + 4H2O H2S + 6HN03(a)->

S O 2 + 6 N O 2 + 4H2O 2H2S + SO2 ^ 3 S + 2H2O

HjS + 2 F e a 3 ^ S + 2 F e a 2 + 2HO

- Tinh axit: axit rat yfi'u, tao 2 loai

mu6'i(S ,HS-):

HjS + N a O H > NaHS + H2O H2S + 2NaOH > NajS +2H2O

H2S + CUSO4 > CuS i + H2SO4

Chat ran, mau vang, khdng

tan trong nirorc

- Tan nhi^u trong nudrc, k h i d6c

Tao ra 2 loai mu6'i:

SO2 + NaOH -> NaHSOj SO2 + 2 N a O H -> Na2S03 + H2O

Tao ra mud'i sunfat:

SO3 + 2 N a O H - >

Na2S04 + H2O

Tac dung voi oxit

baza

SO2 + CaO > CaS03 SO3 + PaO > CaS04

Tinh o x i hoa SO, + 2 M g — ^ S + 2 M g O

SO, + 2H2S > 3S + 2H2O SO2 + 4 H I - > 2I2 + S + 2 H , 0

SO3 + 2 K I > I2 + K2SO3

3 S 0 3 + 2 N H 3^ N 2 +

+ 3SO2 + 3H2O 2SO3 ' ^ ^ ^ > 2SO2 + O2

Tinh khir 2 S O , + 0 2 < >• 2SO3,

V s o S A N H A X I T S U N F U R I C L O A N G V A A X I T S U N F U R I C

Axit sunfuric losing Axit sunfuric dac, n 6ng

DiSn l i H2SO4 > H* + HSO4

HSO4 ^ H* +

S04-H2SO4 > IV + HSO4- (m6t pMn) H2SO4 > H2SO4 (chu ye'u)

5SO2 + 6H2O SO2 + 2H2O

2 C + 4H2SO4 - > 2CO2 + 4SO2 + 4H2O

H + H2SO4 ^ SO2 + 2H2O

+ S O 2 + IOH2O 2Fe(OH)2+4H2S04-> Fe2(S04)3

+ S O 2 + 6 H 2 O 2FeC03+ 4H2S04^ Fe2(S04)3

+ SO2+ 2CO2 + 4H2O

F e j O j + 3H2SO4 > Fe2(S04)3 + SH.O

CuO + H2SO4 > CUSO4 + H2O

2 F e ( O H)3 + 3H2SO4 > Fe2{S04)3 + 6H2O

+ Brj + 2H2O H2SO4 + 8 H I - > H2S +

+12 + 4H2O

j V i U ^ I S U N F U A V A MU6l S U N F A T

Mudi sunfua ( S ' ) Mudisunfat ( S O 4 )

— f f n i v t a n - Hdu he't d^u khdng tan (trCr mudi

sunfua ciia cac k i m loai nhdm l A ,

I I A (trCr BeS), amoni)

- HSu he't d^u tan (tril BaS04, PbS04, SrS04, CaS04)

- Khdng mau: Na.S, KjS, CaS,

- M u d i sunfua tan trong nude, bi thuy phan manh cho m d i trudng kiem:

S- + H 2 O fz> H S + O H "

- M d t sd mudi sunfua nhu AI2S3,

Fe,S3, Cr2S3, M g S bj thuy phan

hoan tokn:

AI2S3 + 6H2O ^ 2A1(0H)3 + 3H2S

- M u d i sunfat tan ciia k i m

loai trung binh hoac y€u bi

thiiy phan tao ra m d i trudng axit:

- M u d i sunfua cua cac k i m loai nang nhu CuS, Ag2S, PbS, HgS,

- Cac mudi nhu BaS04, SrS04, PbS04,

Nhan bie't - Gia'y t^m dung dich Pb(N03 )2,

AgNOj hoac CUSO4, :

B C A C D A N G B A I T A P T R O N G T H I T U Y ^ N S I N K D H - C D

Dang 1: Xdc dinh chat

1 L i thuyet v^in dung va phuong phap giai:

* Cac phurcmg phap giai nhanh thircmg duoc sir dung Ai giai cac bai tap dang nay:

• Phirong phap xac dinh ch&'t dua vao cong thurc tinh phan tur khoi: Gia siJr CQ

chat cho electron la A Ta c6:

-.k

Vay: -.k = n (cho) • M A = — ^

"e(cho)

+ Dua v i o cac dS kiSn bai ra cho, xac djnh duac cac dai luong m^, k,

(^ho)-+ Tinh gia tri

MA-+ Tir phan tir khd'i xac dinh duoc chat cin tim

Phirong phap trung binh: C6ng thiic tinh nguyfin tiif kh6'i trung binh ciia hai

— m

kim loai lidn tifi'p trong ciing ni6t nhom A: M = hh

+ Tinh cac lucmg chat da cho trong bai ra

+ Vid't phuong trinh hoa hoc (sor d6 hoa hoc) su dung ki hidu trung binh

+ Tinh dai luong trung binh thi'ch hop

+ Rut ra ka't luan va tinh cac dai luong theo ydu ciu

Phuong phap bao toan electron: Trong phan ting oxi hoa khiir, t6ng s6 mol

electron do chat khir cho phai diing bang tdng s6' mol electron do chat oxi hoa

nhan:

Z e (cho) = I e (nhan) =:> n,ho N,,h„ = n„hj„.N „h,„

+ Vi6t cac qua trinh oxi hoa, qua trinh khir (khdng c^n vifi't phuong trinh phan

ling oxi hoa - Vhvt)

+ Dat ^n, dua vao djnh luat bao toan electron lap duoc phuong trinh dai sd

+ Giai hd phuong trinh, xac dinh duoc M chat c^n tim

Phirong phap bao toan khoi lirong: Trong m6t phan ling hoa hoc, t6ng khd'i

luong ciia cac chat san ph£m bang t6ng kh6'i lucmg ciia cac chat tham gia phan

ling

Gia six c6 phan ling: aA + bB -> cC + dD

Theo dinh luat bao toan khd'i luong ta c6: m^ + mg = mc + mo

Ap dung: Trong m6t phan ling, c6 n cha't (k^ ca chaft phan ihig va san phim)

n6'u bie't khd'i luong ciia (n - 1) chat thi tinh duoc kh6"i luong cua chat con lai

TO

^ i r o n g phap bien \ukn: M = kn Trong do:

1^- phan tir kh6'i ciia chat hoSc nguydn tir khd'i cua kim loai

- hoa trj (vod k i m loai n = 1, 2 hoSc 3)

Y: 1^ m6t hang so c6 gia tri tuy theo dU kien bai ra

iJsi luot thay cac gia tri n (n = 1,2 va 3) vao bi^u thiic M , tir d6 nit ra chSft cin

tim-M6t PTHH cin luu y: ^ ,

2FeO + 4H2SO4 -> Fe,(S04)3 + SO, + 4H2O , '

2Fe304 + 10H,SO4 3Fe2(S04)3 + SO, + lOH^O

2FeS + 10H,SO4 Fe2(S04)3 + 9SO, + lOH^O

2FeS2 + I4H2SO4 - ) • Fe2 (S04)3 + ISSO^ + MH^O 2FeC03 + 4H2SO4 - > Fe,(S04)3 + SO, + 2CO, + 4H2O

2 Cac thi du minh hoa:

Thidu / : Hoa tan hoan toan 24 gam h6n hop X g6m M O , M(0H)2va MCO3 ( M

la kim loai c6 hoa trj khong d6i) trong 100 gam dung djch H2SO4 39,2%, thu

duoc 1,12 lit khi (dktc) va dung djch Y chi chiia m6t chat tan duy nhaft c6 n6ngd6 39,41%

7-Tatha-y n^,so4 = nH2S04 = 1 ^ = ° ' ^ ( ™ ° 0 (baoto^n s6'mol ion S O ^ )

Theo bai ra: + = 39,41 => M = 24 ( M Ik k i m loai M g )

121,8 Dap an dung la C

^hi du 2: Cho m gam m6t oxit sat phan irng vira dii vod 0,75 mol H2SO4, thu duoc dung djch chi chiia m6t mu6'i duy nhit va 1,68 lit khi SO2 (dktc, san

Ph^m khiJr duy nha't ciia S**) Gia trj cua m la

Vi tao san phim khu SO, => Oxit sat la FeO hoac Fe304

Gia sis oxit sat la FeO:

2FeO + 4H2SO4 Fe2(S04)3 + SO, + 4H2O

' ' ' 0,3 <- 0,075 (mol) ' 'V>"^

Vi s6'mol H,S04 = 0,3 ^ 0,75 loai ' '

Vay oxit sat la Fe304 That vay:

2Fe304 + IOH2SO4 -> 3Fe2(S04)3 + SO, + !0H,O

0,15 0,76 <- 0,075 (mol)

vay m = 0,15 232 = 34,8 (gam)

Dap an dung la B

Thi du 3: Cho Fe tac dung vdi dung djch H,S04 loang tao thanh khi X; nhiet

phan tinh th^ KNO3 tao thanh khi Y; cho tinh thi KMn04 tac dung vdi dung

djch HCl dac tao thanh khi Z Cac khi X, Y va Z l^n lugt la

vay X, Y, Z \in lirot la H,, O, va CI,

Dap an dung la A

Thidu 4: Oxi hoa hoan toan m gam kim loai X cSn vifa du 0,25m gam khi O2 X

la kim loai nao sau day?

' KiTluan Loai Cu Loai

vay X la kim loai Cu

£)iip an dung la C

-^^iT'^iTsTM&t mSu khi thai duoc sue vao dung djch CUSO4, tha'y xuat hidn ke't tiia mau den Hien tufcmg nay do cha't nao c6 trong khi thai gay ra? •

(Trich de thi tuyen sinh DH khoi B) Huong ddn gidi

Khi thai chiJ-a H2S: H2S + CUSO4 CuS i +H2SO4

den D^p 4n <Jung 1^ A- ^

'rhTdu 6: Dot diay hoan toan 7,2 gam kim loai M (c6 hoa trj hai khong d6i

trong hap chat) trong h6n hop khi CI, va O2 Sau phan ling thu dufoc 23,0 gam chat ran va th^ tich h6n hop khi da phan utig la 5,6 lit (d dktc) Kim loai M la

A M g B.Cu C B e D Ca

(Trich de tuyen sinh Cao dang khoi A) Hu&ng ddn gidi

86' mol h6n hop khi da phan ling: n^j, = = 0,25(mol)

So d6 phan umg: M + O2, CI, -> MO, MCh Theo djnh luat bao toan kh6'i lirong: m ^ + m,,h(o2,ci2) ^ '"(r)

=^'"hh02,a2 = " i ( r ) - ' " M =23,0-7,2 = 15,8(g)

Goi X, y Idn lirgt la s6' mol CI,, O,

Taco: < x + y=0,25

Giai ra ta duoc: x = 0,2; y = 0,05 71x + 32y = 15,8

Cic qua trinh oxi hoa khir xay ra:

> 2cr

O2 + 4e 0,05 - ^ 0 , 2

M

20'

^eo dinh luat bao toan electron, ta c6:

7,2n

M = 0,4 + 0,2=0,6 =>7,2n=0,6M =>M = 12n

Ke't luan Loai Mg Loai

Vay kim loai M la Mg

Dap an dung la A

Thi du 7: Chat khi X tan trong nuotc tao ra m6t dung djch lam chuy^n mau qu^

ti'm thanh do va c6 th^ duoc dung lam chat t^y mau Khi X la

Do do dung djch SO, lam quy tim hoa do

Khi SO2 thuomg duoc dung lam chat t^y mau (t^y trang ducmg, gi^y, )

Dap an dung la A

Thi du 8: Cho 0,015 mol m6t loai hofp chait oleum vao nude thu duoc 200 ml

dung djch X Di trung hoa 100 ml dung djch X c^n dung 200 ml dung djch

NaOH 0,15M Ph^n tram ve kh6'i luong ciia nguyfin t6' luu huynh trong oleum

Oleum la H2S2O7 (hay H2SO4.SO3)

Vay thanh ph^n khd'i luong nguydn t6' luu huynh trong oleum:

2.32.100%

= 35,95%

'^''"Is/oleum

Dap dn dung la D 178

rr ^^^'pTHo'i thuy ngSn rat d6c, bdi vSy khi lam v5 nhiet kfi' thiiy ngan thi chat

^ v6i s6'ng B cat C mu6'i Sn D luu huynh

(Trich dethi tuyen sinh DH - CD khoi B) Hu&ng ddn gidi

Chat b6t dung d^ thu gom thuy ngSn (d6c hai) bj roi vai la b6t luu huynh (mau

vang nhat, con goi la didm sinh):

PTPU": Hg(,) +S(,) > HgS(,j„, nipan dung la D

f^fdulO: Cho 0,01 mol m6t hop chat ciia sit tac dung h6't voi H2SO4 dac, nong

(du) thoat ra 0,112 lit (cf dktc) khi SO2 (la san ph^m khir duy nhSft) C6ng thuc

ciia hop chat sat do la A.FeS B FeCOj C. FeS2. D FeO

(Trich dethi tuyen sinh DH - CD khoi B) Hu&ng ddn gidi

Theo bai ra: n SO2 0,112

Chu v; PTPU" ciia cac chat (con lai) vod H2SO4 dac, nong:

2FeS+ IOH2SO4 > Fe2(S04)3 + 9SO,+ IOH2O

2FeC03 + 4H,S04 > Fe2(S04)3 + SO^ + 2C0, + 4H,0

2FeS2 + I4H2SO4 > Fe2(S04)3 + I5SO2 + I4H2O

3 Cac bai tap tir luyen:

^^u 1: Hoa tan hoan toan 20,88 gam m6t oxit sat bang dung djch H2SO4 dac, nong thu duoc dung djch X va 3,248 lit khi SO2 (san phdm khir duy nha't, b dktc) Co

can dung djch X, thu duoc m gam mu6i sunfat khan Gia trj ciia m la