NGHIEN Ctru & LTNG DUNG TANG CiroiUG HU1VG THU HOC TAP CUA HOC SINH TRUNG HOC PHO THONG QUA BAI TAP HOA HOC THUC TIEN ThS Le Thj Thuy Dung Trudng Dgi hpc Hdng Birc SUMMARY The aim of this paper is to[.]
Trang 1TANG CiroiUG HU1VG THU HOC TAP CUA HOC SINH TRUNG HOC PHO THONG QUA BAI TAP HOA HOC THUC TIEN
ThS Le Thj Thuy Dung
Trudng Dgi hpc Hdng Birc SUMMARY
The aim of this paper is to stu(fy how to build Chemistry exercises, whose contents are associated with reality Chemistry reality exercises help students strengthen knowledge, improve critical thinking ability and be interested in learning chemistry To improve the quality of teaching in accordance with our Party and Government's education goals: "Practice makes perfect, education
is combined with working and producing and theory is associated with reality "
Keywords: Excitement of learning, actual exercises chemistry
Ngdy nhpn bdi: 21/4/2014, ngdy duypt dSng: 25/4/2014
Hoa hge la mdn khoa hgc thyc nghifm trgn
CO sd ndm virng \<f thuylt Vice day va hgc phai
gdn ly thuyet vdi thyc hanh, thue tiln ddi song
va san xuat Viec sir dung bai tap cd lien quan
den thyc tien se giup hgc sinh (HS) eung cd kien
thirc, phat huy tinh nSng dgng, sang tag va tao
hijrng thu hgc t^p cua HS ddi vdi mdn hgc Tang
cudng sur dung bai tap thyc tien trong dgy va hgc
Hoa hgc se gdp phan thue hifn nguygn li giao
due "hgc di ddi vdi hanh, giao due kgt hgp vdi
lao dgng san xudt, li lugn gan lien vdi thyc tien"
Thyc t l da chimg minh bai giang cang khoa hgc,
tryc quan, thyc t l thi HS cang dg hilu va nhd
lau Hien nay, trong chuang trinh sach giao khoa
Hda hgc 12, chuang 9 da neu "Hda hgc va vdn
d l phat triln kinh t l , xa hdi, mdi trudng" cang
khdng dinh vai trd quan trgng gdn liln khoa hgc
vdi thyc tiln Tuy nhien, so lugng bai tap hoa
hgc thyc tien (BTHHTT) trong sach giao khoa
cdn it (chilm 11,67% tinh theo tdng sd lugng bai
tap) va viec ldng ghep BTHHTT vao giang day
d timg bai, timg chuong cho phu hgp chua dugc
quan tam dung mure vdi vai trd quan trgng cua
nd Do vay, HS cd thl giai thanh thao cac BTHH
dinh tinh, dinh lugng rdt phirc tap, nhung khi
cdn phai diing kiln thiic hoa hgc d l giai quylt
mgt tinh hudng ey the trong thyc tiln lgi lung
tiing Bk phat huy hifu qua trong day va hgc Hda
hgc, bai vilt dua ra mdt sd BTHHTT giiip HS
THPT cung CO kiln thirc, phat triln nang lyc lu
duy va hutig thii hgc tap
1 Khai Dtf m bai t a p hda hgc thijrc tien BTHHTT la nhtmg BTHH cd ndi dung xuat phat ttjr th\rc tiln, van dyng kien thurc hda hgc vao cugc song va san xudt, gdp phdn giai quyet m^t s6 vdn de dat ra tir thyc tien
Cd the phan logi BTHHTT nhu sau: - Dya vao hinh thai hoat ddng eua HS khi giai bai tgp: chia thanh BT If thuyet va BT thyc nghiem; -Dua vao ti'nh chat cua bai tap: chia thanh BT dinh tinh, dinh lugng, tong hgp; - Dya vao ITnh vyc thyc tiln gdn vdi ngi dung BT: chia thanh
BT ve san xudt hda hge; cac vdn d l trong ddi sdng, lao ddng va san xudt; cac van d l cua mdi trudng
2 Mdt so nguyen tdc khi xSy dyng BTHHTT
Khi xay dyng cac tinh hu6ng gdn vdi thyc tien va sur dung BTHHTT trong dgy hgc Hda hgc can tuan theo eac nguygn tdc sau:
- Dam bao tinh chinh xac, tinh khoa hgc, tinh hien dai Cac dO- lifu thyc tien dua vao BT phai chuan xac va khdng dugc tuy tifn thay doi
- Dam bao tinh thyc tiln Ndi dung cOa
BT phai gan Hen vdi thyc tien cugc song va c6 tinh ung dung cao, dgc bift la gdn gui vdi kinh nghifm cua HS
- Dam bao tfnh trgng tam Ngi dung cua BT phai gan lien vdi ndi dung bai hgc, nhihig kiln thue quan trgng can khdc sSu, ghi nhd
Trang 2- Dam bao tinh logic, ngdn ggn
- Dam bao tinh giao due, tinh su phgm Ngi
dung BT phai phii hgp vdi trinh dg, kha nang
nhan thirc cua HS
' Kich thich himg thii, kha nang sang tao
cua HS
3 Quy trinh thiet ke BTHHTT
BTHHTT dugc thiet ke theo 3 bude sau day:
- Bude 1: x a c dinh muc tieu, ngi dung va
ddi tugng hge tap Giao vien (GV) phan tich
myc tieu, ndi dung bai hgc, nghien cuu trinh do
nhgn thdc cua HS de thiet ke BT cho phii hgp
- Birdc 2: Thiet ke BT va phuong phap giai
BT GV phai dy kiln dugc nhung sai ldm de mac
phai cua HS va dua ra each khde phye
- Bude 3: Phuong phap sur dyng BTHHTT
4 Mgt so bai tSp hda hgc thy-c tien
Bdi 1: Bdng kiln thirc hda hgc, hSy giai
thich:
a Vi sao ta hay dimg cae dd vat lam bang
bac nhu vong bgc, de "danh gid" khi bj bfnh
cam
b Vi sao khi bj ngg dgc sdn, ngudi ta thudng
giai dgc bdng each cho uong nude dudng
c Vi sao khi diing dd vat lam bdng dong
bj gi xanh, ta cd the diing khan tam giam hoac
nude c6t chanh dg lau chiii cho sang nhu mdi
Hirdng ddn: Ddy la nhung kinh nghiem co
CO sd khoa hgc va dugc su dung rgng rai ma
chung ta cdn bilt HS vira phai cd hieu biet nhat
djnh trong thyc te lgi vira nam chdc kiln thurc
hda hgc, co tu duy tot mdi giai thich dugc hifn
tugng tren
a Khi bj cam, trong c o t h l con ngudi se tich
ty mgt lugng khi H^S tuong ddi cao, lam cho co
thl mft mdi Khi ta dimg Ag d l danh gid thi Ag
sg tac dyng vdi khi H^S Milng Ag sau khi danh
gid sg cd mau den xam ciia Ag^S
b sdn chira axit HCN la chdt gay dgc Nude
dudng (saccaroza) khi vao dg day se bj thuy
phan tgo thanh glucozo HCN gap glucozo se cd
phan ung xay ra d nhdm chirc andehit, sau dd tgo
ra hgp chdt de thuy phan giai phdng NH,
c Thanh phdn chinh ciia gidm la axit axetic,
cdn trong nude chanh la axit citric, cae axit nay se
tac dyng vdi gl xanh de lam sach be mat do vat
Bdi 2: De njra sgch chai lg dyng anilin, nen
diing each nao sau day?
A Riia bdng xa phdng
B Rura bdng nude
C Riia bdng dung dich NaOH sau dd nia lai bdng nude
D Rda bang dung djch HCl, sau dd nia lgi bdng nude
Hirdng ddn: Day la mgt van de cd the gap
phai khi lam vifc trong phdng thi nghifm Mudn giai dugc bai tap nay HS phai nam viing tinh chdt eiia anilin, ca tinh chdt vat li (anilin it tan trong nude) va tinh chat hda hgc (anilin cd tinh bazo yeu), ddng thdi phai cd kinh nghiem lam sgch dung cu thi nghiem mdi nhgn ra dugc dap
an dung la D
Bdi 3: Tfnh khoi lugng glucozo chira trong
nude qua nho dg sau khi len men thu dugc 200 lit rugu vang 100 Bilt hieu sudt phan umg len men dat 95%, ancol etylic co khdi lugng rigng 0,8 g/ml
Hu&ng ddn: Day la mdt BTHHTT thugc
logi BT dinh lugng HS phai tim hieu qua trinh lgn men, bilt rugu 100 la rugu nhu the nao, chira bao nhieu ancol etylic nguyen chat, dong thdi ndm chdc kien thurc vl hifu suat phan ung, khoi lugng rieng thi mdi giai dugc bai tgp nay Dap an: 31,3 kg
Bdi 4: Nlu lay mdt sgi day dien ggt bd vd
nhya (PVC) roi dot ldi ddng tren nggn lua den cdn ta thdy nggn lira nhudm mau xanh la ma, sau
do mau nggn lua mdt mau xanh Neu ap ldi day dong dang ndng vao v6 day difn roi dot thi thay nggn lua lgi nhudm mau xanh la ma HSy cho biet nguyen nhan gay ra hifn tugng tren
Hudng ddn: Day la mgt thi nghifm ma HS
cd thl da timg g^p trong cugc sdng, HS thdc mde nhung chua giai thfch dugc Vd day difn lam bdng hgp chat cao phan tu PVC cd cdng thue (C^H^COn, khi d6t tgo thanh COj, H^O va HCl Loi day ddng ludn bam dfnh vao PVC, tac dyng vdi HCl tgo thanh CuCl^, nggn lua mau xanh
la mg chinh la dac trung cua CUj* khi dot Khi CuClj bay hoi hit thi mau nggn lua tgi trd vg nhu cu, mdt mau xanh Ngu cho day dong tilp xiic vdi PVC thi hifn tugng lap Igi BTHHTT nay thugc logi BT djnh tinh
Trang 3Bdi 5: Binh chu'a chay phun bgt cd cau tgo
nhu hinh v e :
Dung dicti
NaHCO,
UigthQy til
^ ho dung
- 6 n g hd mieng dyng dung dich AI (SO J^
- Binh dyng dung dich NaHCOj ndng do
cao
Binh thudng, binh ch&a chay dugc de dung
thang, khdng dugc de nam Khi can chira chay
thi phai ddc ngugc binh len Giai thfch vi sao
phai lam nhu vay
Hudng ddn: BT cung cap cho HS kinh
nghiem khi sir dung binh chu^a chay, kien thue
thyc te nay se co tac dyng rdt Idn trong ddi song
HS phai CO kiln thirc tong hgp ve phan hda vd
CO mdi giai dugc BT tren Khi doc ngugc binh
len thi 2 dung djch trgn lan vao nhau, xay ra
phan irng:
Al3(SO,)3 + 6NaHC03 - ^ 2Al(OH)3 +
3Na,S0, + 6C0j
Khi COj CO tac dung ngan can sy chay Khi
chua cdn cuu hda thi khdng dugc d l nghigng,
lam d6 binh, do dd, binh cuu hda thudng dugc
de trong khung kinh, khi can diang se dap vd
kinh de lay ra
Bdi 6: Axit fomic (HCOOH) cd trong ngc
kiln, ngc ong, sau rdm Khi bi ong, kign ddt
hoac eham vao sau rdm, de khdng bi simg tay ta
chgn chat nao de bdi vao vet thucmg:
A.Vdi tdi
B Gidm an (dung dich axitaxeticCHjCOOH
6%)
C Cdn
D Nude
Hu&ng ddn: Tir BT thyc nghifm nay HS se
giai quyet dugc van de thudng gSp trong cugc sdng dya vao kiln thurc dS hgc Chat chgn d l b6i vao vlt thuong phai trung hda dugc axit fomic,
do dd dap an chon la A
Bdi 7: Dich vj dg day thudng co pH trong
khoang tir 2 den 3 Nhung ngudi nao bi mde bfnh viem loet dg day, ta trang thudng cd pH
< 2 Dg chira can bfnh tren, ngudi bfnh thudng
udng trudc hvta an:
A Nude dudng
B Nude dun sdi d l nguOi
C Dung dich natri hidrocacbonat
D Mgt it giam an
Hudng dSn: Tuong ty bai 6 dap in chgn
laC
Su dung BTHH gdn vdi kien thurc thyc tiln trong bai giang cd tac dyng ciing c6 kiln thiic, ren luyfn tu duy, tgo humg thii hgc t^p cho HS BTHHTT cd the su dyng trong tat ca cdc khau: nghien eihi tai lifu mdi; ciing co, hoan thifn, vgn dung kien thiie, kt nang, kT xao; kilm tra, ddnh gia kien thiie Do dd, sir dyng BTHHTT mft each thudng xuyen trong bai giang la rdt cdn thiet Day thyc sy la mOt bifn phap quan trgng
de nang cao chdt lugng giao dye can dugc GV
va cac nha quan If giao dye quan tam diing miic
Tai lifu t h a m khao
1 Nguygn Hull DTnh - Lg Xuan Trgng Bdi tap dinh tinh vd cdu hoi thue ti hod hpc 12 (tgp
1 - Hod hpc him co) NXB Giao dye, H 2001
2 Cao Cu Giac Bdi tdp ly thuyet vd thycc nghiem hod hpc (tgp 2 - Hod hpc hieu co) NXB
Giao due, H 2006
3 Nguyen Cucmg - Nguygn Mgnh Dung
Gido trinh Phirong phdp dgy hpc Hda hpc (tgp III) NXB Dai hgc Su phgm, H 2007
4 Nguyin Xuan Trudng Su dung bdi tgp trong dgy hpc Hod hpc d trudng phd thong
NXB Dgi hgc Su pham, H 2006
5 Lg Xuan Trgng (chii bien) SGK Hoa hpc
10, 11, 12 Ndng cao NXB Giao dye, H 2006
6 Lg Xuan Trgng (chii bign) SGK Bdi tap Hda hpc 10, II, 12 Ndng cao NXB Giao due,
H 2006