slide 1 group viia the halogens halogens greek hals “salt” genes “born” tính chất lý học tính chất hóa học điều chế và ứng dụng hidro halogenua hợp chất chứa oxi của halogen department of inorgan

Hydrobromic acid is formed by the direct union of hydrogen and bromine in the presence of a catalyst, such as platinum; another method is to brominate phosphorus to [r]

GROUP VIIA The Halogens

Halogens (Greek hals , “salt”; genes , “born”)

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2 *2 2 2 2 *2 *2

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The Lewis dot structure

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Isotopes

Cl-35 makes up about 75% of chlorine

atoms in nature, and Cl-37 makes up the

remaining 25%

the average atomic mass of Cl is 35.45

amu

protons and 18 neutrons (35 - 17)

• Halogens are fluorine, F; chlorine, Cl; bromine, Br; iodine, I; and astatine,

At.

• Halogens contain 7 valence electrons.

• As elements, halogens are diatomic.

• Fluorine is a reactive, pale, yellow gas.

• F is used in compounds of carbon to form fluorocarbons

– Teflon is an example of a fluorocarbon.

– Other fluorocarbons include the Freons used as refrigerants.

– Many fluorocarbons are no longer used because of their effect on the

ozone layer.

• Chlorine is a reactive green-yellow gas.

– Cl2 used to purify water and in the

production of paper, textiles, bleaches, medicines, and other consumer products.

• Bromine is a red liquid

– Br is used in photographic chemicals,

dyes, pharmaceuticals, and fire retardants.

• Iodine is a crystalline solid.

– I2 sublimes, turns directly from a solid to a gas

when heated.

– Iodine is present in brine fields in oil field in

California and Louisiana and in sea plants.

– Iodine compounds are used in photographic

chemicals and medicines.

– Iodine is required by the human body in the thyroid.

• All isotopes of astatine are radioactive.

Ionic radii

Cation formation

vacates outermost orbital

and decreases e-e repulsions

SIZE DECREASES

Anion formation increases e-e repulsions

so they spread out more

SIZE INCREASES

**

Phân tử E A-A

[kJ/mol]

Độ dài LK [Å]

151 239

190 149

2.67 3.08 3.92

1.42 1.99 2.28 2.67

F không có orbital hóa trị

d tham gia liên kết

Orbital hóa trị tăng dần các:

Năng lượng

Số lượng tử chính: n

Số nút hàm xuyên tâm: n-l-1

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Năng lượng liên kết cộng hóa trị E cht

Độ xen phủ của các orbital hóa trị lớn khi:

- Miền xen phủ rộng và mật độ e ở miền xen phủ lớn

- Z’ đối với orbital hóa tị lớn

- Số lượng tử chính n nhỏ

- Hiệu năng lượng các orbital hóa trị trong nguyên tử và giữa các nguyên tử tham gia liên kết là nhỏ

- Số nút hàm xuyên tâm của của orbital hóa trị là ít (số nút = n – l -1)

- Ở miền xen phủ có nhiều orbital hóa trị tham gia

Yếu tố quyết định năng lượng liên kết là bậc liên kết Khi bậc liên kết bằng nhau nhưng E cht khác nhau là do độ xen phủ các orbital hóa trị là khác nhau.

Trong 1 chu kỳ, từ trái qua phải:

- Z’ đối với các orbital hóa trị tăng dần  Echt tăng dần

- Hiệu năng lượng các orbital hóa trị, Enp-Ens, giảm dần  Echt giảm dần

Tổng Echt sẽ là giá trị cạnh tranh giữa 2 xu hướng này

Trong 1 phân nhóm A, từ trên xuống:

- Năng lượng các orbital hóa trị cùng dạng tăng dần.

- Số lượng tử chính n của các orbital hóa trị tăng làm số nút hàm xuyên

tâm tăng.

 E cht giảm dần.

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Năng lượng liên kết F-F nhỏ

Ái lực với electron lớn

Năng lượng liên kết của F với nguyên tố khác lớn

Khả năng hidrat hóa của ion F- lớn

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Nổ khi đun nóng hoặc ánh sáng

tử ngoại

Bắt đầu ở

2000C, trên

7000C có phản ứng nghịch

Bắt đầu ở

2000C, là phản ứng thuận nghịch

0

298,s

H



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Department of Inorganic Chemistry - HUT

F 2

Fluorine (Latin fluo, “flow”), symbol F, chemically reactive, poisonous gaseous element The atomic number of fluorine is

9

Fluorine occurs naturally in the combined form as

compounds are generally derived, is commonly mined

in the United States from large deposits in northern

Kentucky and southern Illinois Fluorine also occurs as

fluorides in seawater, rivers, and mineral springs, in the

stems of certain grasses, and in the bones and teeth of

animals It is the 17th element in order of abundance in

the crust of the earth

1886 French chemist Henri Moissan.

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CaF 2FLUORITE, "The Most Colorful Mineral in the World"

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Cryolite, mineral, sodium aluminum fluoride (Na3AlF6) Cryolite has

a hardness of 2.5 and a specific gravity of about 3 It crystallizes in the monoclinic system (see Crystal) It is colorless and ranges from transparent to translucent It has a waxy appearance, making it almost invisible when powdered and suspended

in water Cryolite was found in abundance only at Ivigut, Greenland However, that deposit has been exhausted since 1987 The mineral is still found in small

quantities in Colorado, USA; Sallent, Huesca Province, Spain; Miask, Urals, USSR; and Montreal, Quebec, Canada It is used chiefly as a solvent of alumina in the

electrolytic preparation of aluminum Because of its scarcity, this mineral has been replaced in industrial processes by artificially produced sodium aluminum fluoride

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Apatite (Greek apate, “deception”), mineral so named because it resembles various other minerals for which it might be mistaken It consists chiefly of phosphate of lime Apatite is a distinct mineral of composition Ca5(PO4)3F in which some or all of the fluorine may be replaced by chlorine (chlorapatite) The mineral crystallizes in the

hexagonal system (see Crystal) and has a hardness of 5 and a specific gravity of 3.2 When pure, apatite is colorless and transparent, but it may exhibit various degrees of color and opacity These mineral phosphates of lime were often used in the preparation

of fertilizers, but they have been replaced by phosphate rock

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The preparation of fluorine as a free element is difficult and seldom done, since free fluorine is very reactive However, gaseous fluorine

gas through a metal or rubber tube surrounded by liquid air

Fluorine compounds have many applications The chlorofluorocarbons, odorless and

dispersing agent in aerosol sprays and as a refrigerant In 1974, however, some

scientists suggested that these chemicals reached the stratosphere and were destroying the earth's ozone layer With confirmation of these findings by the late 1980s, the

production of these chemicals began to be phased out (see Environment) Another

is widely used to make such products as motor gaskets and dashboard accessories in the automobile industry Teflon is also used as a coating on the inner surface of frying pans and other kitchen utensils to reduce the need for fat in cooking Many organic

fluorine compounds developed during World War II (1939-1945) showed extensive

commercial potential For example, the liquid fluorinated hydrocarbons derived from

diffusion process to provide fuel for atomic power plants

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Cl 2Chlorine, symbol Cl, greenish-yellow gaseous element In group 17 (or

VIIa) of the periodic table, chlorine is one of the halogens The atomic

number of chlorine is 17

Elementary chlorine was first isolated in 1774 by the Swedish chemist Carl Wilhelm Scheele, who thought that the gas was a compound; it was not

until 1810 that the British chemist Sir

that chlorine was an element and gave it its present name.

KMgCl3 - 6H2O, Hydrated Potassium Magnesium Chloride

CARNALLITE

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The gas has an irritating odor and in large concentration is dangerous; it was the first substance used as a poison gas in World War I (1914-1919) (see Chemical and Biological Warfare).

KCl, Potassium Chloride

HALITENaCl, Sodium Chloride

4 HCl MnO     dunnhe 2 H O MnCl   Cl 

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Most chlorine is produced by the

electrolysis of ordinary salt solution, with

sodium hydroxide as a by-product

Because the demand for chlorine exceeds

that for sodium hydroxide, some industrial

chlorine is produced by treating salt with

nitrogen oxides or by oxidizing hydrogen

chloride Chlorine is shipped as a liquid in

steel bottles or tank cars It is used for

bleaching paper pulp and other organic

materials, destroying germ life in water,

and preparing bromine, tetraethyl lead, and

other important products

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Bromine has been used in the preparation

of certain dyes and of dibromoethane

(commonly, ethylene bromide), a

constituent of antiknock fluid for leaded

gasoline Bromides are used in

photographic compounds and in natural

gas and oil production

     

growth-controlling and other

stunted growth and conditions such as goiter can result Thus in areas where iodine is not sufficiently abundant naturally, iodine-containing salt serves to make up the deficit In medicine, iodine-alcohol solutions and iodine complexes have been used as antiseptics and disinfectants Radioisotopes of iodine are used in medical and other fields of research More broadly, various iodine

compounds find use in photography, the making of dyes, and cloud-

seeding operations In chemistry, various iodine compounds serve as strong oxidizing agents, among other uses

Thyroid Gland, endocrine gland found in almost all vertebrate animals and so called because it is located in front of and on each side

of the thyroid cartilage of the larynx It secretes a hormone that controls metabolism and growth.

2

3 3 4 4 2 2

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Astatine (Greek astatos, “unstable”), symbol At, radioactive element that is the heaviest of the halogens The atomic number of astatine is 85.

Originally called alabamine because of early research with the element at Alabama Polytechnic Institute, it was prepared in 1940 by bombarding bismuth with high-

energy alpha particles The first isotope synthesized had

an atomic weight of 211 and a half-life of 7.2 hours

Subsequently, astatine-210 was produced and found to have a half-life of about 8.3 hours Isotopes of astatine with mass numbers from 200 to 219 have been

cataloged, some with half-lives measured in fractions of

0

X

AG

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-4.2 404.5 1320.2 -366.8 -1393.4 -39.7

-4.2 339.1 1320.2 -345.4 -1363.7 -54.0

-4.2 272.2 1320.2 -315.3 -1330.2 -57.3

Hydrogen Chloride, colorless, corrosive, nonflammable gas, formula HCl, with a characteristic penetrating, suffocating odor It melts at - 114.22° C, boils at - 85.05° C, and has a density of 1.268 (air = 1.000) Hydrogen chloride dissolves readily in water: 1 vol of water at 20° C absorbs 442 vol of hydrogen chloride gas at atmospheric pressure The resulting solution—hydrochloric acid—contains 40.3 percent hydrogen chloride by mass and has a specific gravity of 1.20 This solution fumes strongly in moist air, but dilution stops the fuming Hydrogen chloride becomes less soluble in water as the water temperature rises, and it is less soluble in alcohol, ether, and in other organic liquids.

In solution in water, the molecules of hydrogen chloride ionize, becoming positively charged hydrogen ions and negatively charged chloride ions Because it ionizes easily, hydrochloric acid is a good conductor of electricity The hydrogen ions give hydrochloric acid its acidic properties, so that all solutions of hydrogen chloride and water have a sour taste; corrode active metals, forming metal chlorides and hydrogen; turn litmus red; neutralize alkalies; and react with salts of weak acids, forming chlorides and the weak acids

Hydrogen chloride is produced industrially as a by-product of the reaction of chlorine with hydrocarbons to produce organic chlorides Hydrochloric acid may be made by the reaction of sodium chloride with sulfuric acid or

by combining hydrogen and chlorine Crude industrial hydrochloric acid is called muriatic acid It is used in large quantities in the preparation of chlorides and for cleaning metals and in industrial processes such as preparation

of corn syrup and glucose from cornstarch Small amounts of hydrochloric acid are secreted by cells in the lining

of the stomach to aid in food digestion.

Hydrobromic acid is a solution of hydrogen bromide gas, formula HBr, and water The gas is colorless, with a penetrating odor, boiling point - 67° C Hydrobromic acid is formed by the direct union of hydrogen and bromine in the presence of a catalyst, such as platinum; another method is to brominate phosphorus to form phosphorus tribromide, which hydrolyzes in water to form phosphorous acid and hydrobromic acid (see Hydrolysis) Hydrobromic acid, like hydrochloric acid, is a strong acid It reacts with metals, some salts, and bases to form bromides.

Hydriodic acid is a solution of hydrogen iodide gas and water, with the formula HI The gas is colorless, with

a penetrating odor, boiling point -35° C Hydriodic acid is formed in the same manner as hydrobromic acid It is less stable than any of the other acids described above, and it decomposes readily into iodine and hydrogen Hydriodic acid is often used as a reducing agent.

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Covalent Oxides

F2O(g) + H2O(l)  2HF(aq) + O2(g)

Cl2O(g) + H2O(l)  2HOCl(aq)

Cl2O7(l) + H2O(l)  2HClO4(aq)

-Cl2O7(s)

Các hợp chất này đều không bền và ít có ứng dụng trong thực tế

NAMING OXOANIONS - EXAMPLES

Prefixes Root Suffixes Chlorine Bromine Iodine

per “ ” ate perchlorate perbromate periodate [ ClO4-] [ BrO4-] [ IO4-]

“ ” ate chlorate bromate iodate [ ClO3-] [BrO3-] [ IO3-]

“ ” ite chlorite bromite iodite [ ClO2-] [ BrO2-] [ IO2-]

hypo “ ” ite hypochlorite hypobromite hypoiodite [ ClO -] [ BrO -] [ IO -]

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Department of Inorganic Chemistry - HUT

Department of Inorganic Chemistry - HUT

HOCl có tính chất oxi hóa mạnh nên nước Javen

và CaOCl2 ứng dụng để tẩy trắng và tẩy uế

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hóa mạnh

Điện phân không

màng ngăn dung

dịch KCl nóng

Ion clorat oxi hóa Cl-, Br-, I- trong môi trường axit

Không xảy ra trong môi trường trung tính, kiềm

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Axit pecloric là axit mạnh nhất trong các axit

P, S, C

Ngòi nổ

Pháo hoa

• Inorganic compounds are substances not

considered to be derived from hydrocarbons

• The rules for naming, or nomenclature, of

simple inorganic compound is covered now (organic nomenclature is covered later)

• Binary compounds are compounds

comprised of two different elements

• The goal is to be able to convert between the chemical formula and the name

• The first element in the formula is identified

by its English name, the second by

appending the suffix –ide to its stem (eg

compound AB)

Chemical Name as Name as

Symbol Stem First Element (A) Second Element (B)

O ox- oxygen oxide

S sulf- sulfur sulfide

N nitr- nitrogen nitride

P phosph- phosphorus phosphide

F fluor- fluorine fluoride

Cl chlor- chlorine chloride

Br brom- bromine bromide

I iod- iodine iodide