sulphur dioxide and

8/4/2019 Sulphur Dioxide And

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SULPHUR DIOXIDE AND

ENVIRONMENTAL

POLLUTION

1.Sulphur dioxide is one of the by-product of contact process. Itis a colourless and

poisonous gas with a vary pungent smell.

2.Sulphur dioxide which escape into the air causes air pollution.

3.Sulphur dioxide is an acidic which dissolves in water to form

sulphurous acidic, H2SO3.

In the atmosphere, sulphur dioxide dissolve in water droplets to

form sulphurous acidic.

4.Oxidation of sulphur acid by oxygen produce sulphuric acid,

H2SO4, which falls to the earth as acid rain. Sulphur trioxide is

also easily oxidised in the air to form sulphur trioxide. Sulphur

trioxide dissolve in rainwater to produce sulphuric acid.

USES OF AMMONIA

1.Ammonia that is produce commercially has many uses.

2.It uses:

i.In the manufacture of chemical fertilizers such as ammonium

sulphate, ammonia



nitric, ammonia phosphate and urea.

ii.To manufacture nitric acid and explosive.

iii.In the making of synthetic fibre and nylon.

iv.As a degreasing agent in aqueous form to remove greasystains in the kitchen.

PROPERTIES OF AMMONIA GAS

1.The physical properties of ammonia gas include the following:

i.It colourless and has a pungent odour.

ii.It is vary soluble in water and form a weak alkaline solution.

iii.It less dense then water.iv.It easily liquified (at about 35.5°C) when cool.

2.The chemical properties of ammonia gas:

a) Ammonia gas dissolves in water to form a weak alkali.

NH3(g) + H2O(l)

NH4+(aq) + OH-(aq)

b) The presence of hydroxide icon causes the aqueous solution

to become alkaline. Thus

aqueous ammonia solution:

i.

T

urns red litmus paper blue.

ii.

R

eacts with acid to form only salt and waterin neutralization

reaction.

NH3(aq) + HCI(aq) NH4CI(aq)

2NH3 + H2SO4(aq) (NH4)2SO4(aq)



iii.

R

eacts with solution of metallic cations to produce precipitates.

Fe²+(aq) + 2OH(aq) Fe (OH)2(s)

(Form ammonia solution)Dirty green precipitate

MANUFACTURE OF AMMONIA IN INDUSTRY

1. Ammonia is manufacture on a large scale in industry through

the haber process. In this process, ammonia is formed form

direct combination of nitrogen and hydrogen gas in the volume

ratio 1:3.

2. The gas nitrogen obtain form the fractional distillation of

liquefied air. The hydrogen gas is obtained form the cracking of

petroleum or from the catalysed reaction of natural gas, CH4,

with steam.

CH4(g) + H2O(g) CO(g) + 3H2(g)

3.The mixture of nitrogen and hydrogen gases is passed over aniron catalyst under

controlled optimum condition as below to form ammonia gas.

i.Temperature: 450-500°C



ii.Pressure: 200-500 atmospheres

iii.Catalyst used: Iron fillings

N2(g) + 3H2(g)

2NH3(g)

4.Under these control optimum condition, only 15% of the gas

mixture turn into ammonia gas. The nitrogen and hydrogen

that have not reacted are then flow back over the catalyst again

in the reactor chamber.

5.The ammonia product is then cooled at a low temperature sothat it condenses into a

liquid in the cooling chamber.



AMMONIUM FERTILIZERS1. Nitrogen is required in large amount by plant to make

proteins which are necessary for growth and cell repair.

2. Most plant are not able to get a nitrogen supply directly from

the air although it is abundant in the air (78%). Plants can only

absorb soluble nitrogen compounds from soil through their

roots.

3. The nitrogen compounds are usually soluble nitric salt,

ammonia and ammonia salt which are manufacture as chemical

fertilizer.

4. Reactions of ammonia with acids produce ammonium

fertilizers.

NH3(aq) + HNO3(aq) NH4NO3(aq)

Ammonium nitrate3NH3(aq) + H3PO4(aq) (NH4)3PO4(aq)

Ammonium phosphate

2NH3(aq) +H2SO4(aq) (NH4)2SO4(aq)

Ammonium sulphate



ARRANGEMENT OF ATOMS IN MATELS

1. The atom of pure metals are packed together closely. Thiscauses the metal to have a high density .

2. The forces of attraction between atoms (metallic bonds) are

strong. More heat energy is needed to overcome the metallic

bond so that the atoms are further apart during the melting.

This is why metals usually have hight melting point.

3. Heat energy can be transferred easily from one atom to thenext by vibration. This make metal good conduct of heat.

4. The freely moving outermost electrons within the metal’s

structure are able to conduct electricity. Metal are, therefore,

good electrical conductors.

5. Since atoms of pure metal are of the same size, they are

arranged orderly in a regular layered pattern. When a force isapplied to metal, layer of atom slide easily over one another.

This make pure metals soft, malleable and ductile.



WHAT ARE ALLOYS

1. Pure metal are usually too soft for most uses. They also have

a low resistance to corrosion. They rush and tarnish easily.

2. To improve the physical properties of metal, a small amount

of another element (usually metal) is added to form another an

alloy.

3. An alloy is a mixture of two or more metals (something non-

metal) in a specific proportion. For example:

a. Bronze (90% of copper and 10% of tin)

b. Steel (99% of iron and 1% of carbon)

4.The purposes of making alloys include the following:

a) Increase the strength

i. Pure iron is soft and vary malleable. When a small amount of

carbon is added to iron, an alloy, steal is formed. The more

carbon is added, the stronger the steel becomes.

ii. Pure aluminium is light but not strong. With a small amount of

copper and magnesium are added to aluminium, a strong, light

and durable alloy call duralumin is produced.

b) Improving the resistance to corrosion

i. Iron rust easily but stainless steel which contains 80.6% of iron,

0.4% of carbon, 18% of chromium and 1% of nickel does notrush. These properties make stainless steel suitable for making

surgical instrument and cutlery.



ii. Pure copper tarnish easily. When zinc (30%) is added, the

yellow alloy which is

known as brass develops a high resistance to corrosion.

c) Enhancing the appearancei. Pewter, an alloy of tin (97%), antimony and copper is not only

hard but also has

a more beautiful white silvery appearance.

ii. When copper is mixed with nickel to form cupronickel, an alloy

that has an attractive silvery, bright appearance is formed

which is suitable for making coins.



Alloy



Composition

Properties

Uses

High carbon steel99% iron

1% carbon

Strong,hard and high

wear resistance

• Making of cutting

tools, hammers and

chiselsStainless steel

80.6% iron

0.4% carbon

18%chromium

1% nickel

Do not rust andtarnish, strong and

durable

• Making of surgical

instrument, knives

forks and spoons

Brass70% copper

30% zinc

Hard, do not rust,

bright appearance



• Making of

ornaments,

electrical wiring

and plug.

Bronze

90% copper

10% tin

Hard, do not corrode

easily and durable

• For casting bells,medals, swords

and statues

Pewter

96% tin

3% copper

1% antimony

Ductile and

malleable, white

silvery appearance

• Making of

ornaments,souvenirs and

mugs

Duralumin



93% aluminium

3% copper

3%magnesium

Light, strong and

durable

• Making part of

aircrafts and racing

cars

Cupronickel

75%copper

25%nickel

Attractive, silvery

appearance, hard and

tough

• Making of silver

coins

WHAT ARE POLYMER



1.Molecule that consist of a large number of small identical or

similar units joined together repeatedly are called polymer.

2.The smaller molecules that make up the repeating unit in

polymer are caller monomer.3.The process of joining together a large number of monomers

to form a long chain polymer is called polymerisation.

4.Polymer can be naturally occurring or man-made (synthetic).

Natural polymer are found in plant and in animals for example

of natural polymers are starch cellulose, protein and rubber.

5.Two type of polymerisation in producing synthetic polymerare additional polymerisation.

6.Double bonds between two carbon atoms usually undergo

addition polymerisation.

Some Common Addition Polymers

Name(s)

Formula

MonomerProperties

Uses

Polyethylene

low density

(LDPE)

–(CH2-CH2)n –ethylene

CH2=CH2soft, waxy solid

film wrap,

plastic bags

Polyethylene



high density

(HDPE)

–(CH2-CH2)n –ethylene

CH2=CH2rigid, translucent

solid

electrical

insulation

bottles, toys

Polypropylene(PP) different

grades

–[CH2-

CH(CH3)]n –

propylene

CH2=CHCH3

atactic: soft, elastic

solid

isotactic: hard,

strong solid

similar to LDPE

carpet,

upholstery

Poly(vinyl

chloride)

(PVC)



–(CH2-

CHCl)n –

vinyl chloride

CH2=CHClstrong rigid solid

pipes, siding,

flooring

Poly(vinylidene

chloride)

(Saran A)

–(CH2-CCl2)n –

vinylidene

chloride

CH2=CCl2

dense, high-melting

solidseat covers, films

Polystyrene

(PS)

–[CH2-

CH(C6H5)]n –

styrene

CH2=CHC6H5

hard, rigid, clear

solid



soluble in organic

solvents

toys, cabinets

packaging

(foamed)



WHAT ARE GLASS

1.Glass is one of the most useful but inexpensive materials in

the world. Many products are

made from glass because of its specials properties.

2.Glass is:

a. Transparent, hard but brittle.

b. A heat and electric insulator.

c. Resistant to corrosion.

d. Chemical not reaction and therefore resistant to chemical

attack.

e. Easy to maintain.

Type of glass

Composition

Properties

Uses

Fused glass

SiO2: 100%

• Transparent

• High melting point

• Good heat

insulator

• Lens

• Telescope mirrors

• Laboratory



apparatus

Soda-lime glass

SiO2: 75%

Na2O:15%

CaO: 9%

Other:1%

• Low melting point,

easily molded into

desired shape andsize

• Low resistant to

chemical attacks

• Brittle

• Drinking glass,

bottles

• Electric bulbs

• Window glass

Borosilicate glass

SiO2: 78%

B2O3: 12%

Na2O: 5%

CaO: 3%Al2O3:2%

• Resistant chemical

attack and durable



• High melting point

• Good insulator to

heat

• Cooking utensils• Laboratory

glassware such as

conical flaks and

boiling tube

Lead crystal glass

(flint glass)

SiO2: 70%

Pbo/PbO2:20%

Na2O: 10%

• High refractive

index

• High density

• Attractive

glittering

appearance

• Lenses and prisms

• Decorative

glassware and art

object

• Imation jewellery



C ERA MI C S

1. Traditional silicate ceramics are made by heating

aluminosilicate clay such as kaolin toa vary high temperature.

2. Ceramics have many special properties that make them one

of the most useful materials



in our everyday life. That:

a. Are hard, strong but brittle

b. Have high melting point and remain stable at high

temperaturec. Are heat and electric instrument

d. Are resistant to corrosion and wear

e. Are chemically not reactive

f. Do not readily deform under stress

3. Ceramic play important role in our daily life. They are uses as

a. Construction materials

i. Ceramic are strong and hard, uses to make roof tiles, bricks

cement, sinks, and

toilet bowls.

ii. They are also used to make refractory bricks because high

resistant to heat.

b. Decorative items

i. To make pottery, china plates, and porcelain vases since they

do not tarnish

easily and are durable.

ii. They are used to make bathroom fixture such as floor and

wall tiles.

c. Electrical insulator

i. Ceramic are used to make electrical insulator in electrical

items such as toasters,fridges and electrical plug.



WHAT ARE COMPOSITE MATERIALS

1. A composite materials (or composite) is a structure of

materials that is formed by two

or more different substances such as metal, glass, ceramic and

polymer.

2. Some common composite materials are:a. Reinforces concrete

b. Superconductor

c. Fibre optic

d. Fibre glass



e. Photochromic glass

REINFORCES CONCRETE

1. Concrete is hard, fireproof, waterproof, comparatively cheap

and easy to maintain. It ismore important construction materials.

2. The reinforces is a combination of concrete and steel.

SUPERCONDUCTOR

1. Metal such as copper and aluminium are good conductor of

electricity, but 20% of the

electric energy is lost in the form of heat during transmission.

2. Super conductor are materials that have no resistance to theflow of electricity at a

particular temperature. Hence, 100% electricity transmission is

possible.

3. One of the most dramatic properties of a superconductor is its

ability to levitate a magnet. Superconductor are used to build

magnetically levitate high-speed train (at about 552 km/h).

4. Superconductor are used to make chips for smaller and faster

supercomputer. Superconductor also play an important role in

high speed data processing in internet communication.

FIBRE OPTIC

1. Fibre optic is a composite material that in used to transmit

signals for light wave.2. Fibre optic is used in

a.

Telecommunicate where the telephone substation are liked by

fibre optic cables.



b.

Domestic cable television network

c.

Closed circuit television security system.3. Fibre optic also used in medical fields. It is used in a number

of instrument which

enable the investigation for internal body part without having

to perform surgery.

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