Folio Chemis Ayiep

8/4/2019 Folio Chemis Ayiep

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SULPHURIC ACID

Manufacture of sulphric acid

1) Sulphric acid can be prepared by using the contact proses using vanadium(V) oxide as catalyst.

2) There are three main stages in manufacturing of sulphric acid namely

a) combustion of sulphur.b) conversion of sulphur dioxide to sulphur trioxide.

c) formation of sulphuric acid.

3) The process at each stage is summarized in table 1.

uses ofsulphric

acid

fertilizer38%

detergent12%

paints 13%

chemicals18%

other uses18%

cleaningmetal 1%


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table 1

Environmental problem of sulphur dioxide

1) Sulphur dioxide is released to the air from the burning of sulphur and the burining of coal.

2)The sulphur dioxide is oxidised to sulphur trioxide by used the oxidizing agent in the ozone.

3)The sulphur trioxide forms acid rains which dissolves in the rainwater.

4)Some of the environmental problems caused bya acid rain are:

a)pollution by increasing the acidity of soil,rivers and pond

b)corrosion of metallic structures

c)corrosion of marble structures

stage 1 : Combustion ofsulphur

sulphur is burn in teair to producesulphur dioxide

sulphur dioxidemust be purified toremove foreigncompounds whichmay poison thecataystS(1)+O2(g)>SO2(g)

stage 2: coversion ofsulphur dioxide tosulphur trioxide

the sulphur dioxideproduced togetherwith air are passedover vanadium oxide(V2O5) catalyst attempreature of 450-500 oC to producesulphur trioxide

SO2(g)+O2(g)>2SO3(g)

stage 3: formation ofsulphric acid

sulphric trioxide isdissolved inconcenrated sulphuricacid to form oleum(H2S2O7)

SO3(g)+H2S2O4 (1)>H2S2O7 (1)

oleum is diluted withwater to producesulphric acid

H2S2O7+H2O(1)>2H2SO4(1)


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AMMONIAUses of ammonia

1) Agriculture consumes nearly 80% of all ammonia produce in the world .

2) Some of the examples of industries associated with ammonium salts are summarized in table 9.3

Industries Uses

ammonium sulfate, (NH4)2SO4

ammonium phosphate, (NH4)3PO3

ammonium nitrate, NH4NO3

urea CO(Nh2)2

Fertilizers

synthesis of:

nitric acid HNO3 which is used in making explosives

sodium hydrogen carbonate

sodium carbonate Na2CO3Chemicals

ammonium nitrate NH4NO3Explosives

nylon,-[(CH2)4-CO-NH-(CH2)6-NH-CO]Fibres & plastic

used for making ice,large scale refrigerator

plants,air-conditioning units in building and plantsRefrigeration


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Poperties of ammonia

1) Physical properties of ammonia

a)colourless gas

b)pungent smellc)very soluble in water

d)an alkaline gas

e)less dense than air

2) Chemical properties of ammonia :

a)reacting as a base

-dissolve into water to give an alkaline solution

NH3(g) + H2O(1) NH4+(aq)+OH-(aq)

Undergoes neutralisation with acids to form ammonium salts

Ammonium +acid > ammonium salts

b)react with aqueous metal ions

metal oxide combine with the hydroxide ions from aqueous ammonia to produce insoluble metal hydroxide


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MANUFACTURE OF AMMONIA IN INDUSTRY

1.Ammonia is manufacture on a large scale in industry through the haber process. In thisprocess, ammonia is

formed form direct combination of nitrogen and hydrogen gas inthe volume ratio 1:3.

2. The gas nitrogen obtain form the fractional distillation of liquefied air. The hydrogen gasis 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 an iron catalyst under

controlled optimum condition as below to form ammonia gas.

i.Temperature: 450-500C

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 ammoniagas. The nitrogen and hydrogen that have not reacted are

then flow back over the catalystagain in the reactor chamber.5.The ammonia product is then cooled at a low temperature so that it condenses into

liquid in the cooling chamber


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ALLOYS

PROPERTIES OF PURE METALS

Certain properties of pure metals are dependent on bond forces, change periodically in magnitude with continuously ascending atomic number,

and show some regular change of magnitude for metals belonging to the same subgroup of the Periodic Table. The increase and decrease of the

elastic moduli with continuously ascending atomic number proceeds simultaneously with similar directions of change in Mohs Hardness, the latent

fusion heat and the specific heat capacity. An example is the linear relation between the Young's modulus and the Mohs hardness of fcc-metals or

the linear dependence of the Mohs hardness and the latent fusion heat. The dependence of specific heat capacity can be also linear for some fcc

and bcc metals. For metals belonging to the same subgroup there exists a similar magnitude sequence for the Young's modulus and for the

corresponding Mohs hardness, and a reverse magnitude sequence for the Young's modulus and the thermal expansion coefficient .

Arrangement of atom in metal


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Mean of alloys

1) An alloy is a combination,either in solution or as a compound of two or more elements with at least one of which being a metal

and the resulting materials has metallic properties.

2) The resulting metallic substance generally has properties significant different from those of its components3) Alloy are usually designed to have properties that are more desirable than those of their component .

Arrangement of atom in alloys


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Purpose of producing alloy

a)To increase the strength and hardness of the pure metals

b)Prevent corrosion of metal

c) Repair of metal appreance to look more attractive

Composition,properties and uses of alloy


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SYNTHETIC POLYMERS

Mean of polymer and monomers

1)Polymer is a term used to describe large molecules consisting of repeating structural units called monomer.

2)Monomer is a small molecule or sub-unit of a polymer

Example of natural polymer

Polymers Properties and polymer structure

is a complex carbohydrate

major constituents of woody plants consists of a long straight chain of glucose

monomers

Celullose

is a complex carbohydrate

is mostly stored in plant seed and tubers

consists of long staright chain of glucose monomerswith different ways of joining

Starch

consists of long chains of isoprene monomersNatural rubbers


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Examples of synthethic polymer


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THE EFFECT OF THE USES OF SYNTHESIS POLYMERS TO OUR

ENVIRONMENT

The use of synthetic polymers, however results in environmental problems

Most polymers are not biodegradable. Polymers cannot be decomposed biologically ornaturally by bacteria or fungi as in the case of other garbage. Thus, the disposal of polymers

has resulted in environmental pollution because they remain in the environment forever.

Discarded plastic items may cause blockage of drainage systems and rivers thus causingflash floods.

Plastic containers and bottles strewn around become good breeding places for mosquitoeswhich cause dengue fever, or malaria.

Small plastic items that are thrown into the rivers, lakes and seas are somethings swallowedby aquatic animals. These animals may die fromchoking.

The open burning of plastics gives rise to poisonous and acidic gases like carbon

monoxide, hydrogen chloride and hydrogen cyanide. These are harmful to the environmentas they cause acid rain.

Burning of plastics can also produce carbon dioxide, too much of this gas in the atmosphereleads to the `green house effect'.

The main source of raw materials for the making of synthetic polymers isp etro leu m.

Petroleum is a nonrenewable resource.

Ways to prevent environment problem

Recycling polymers: Plastics can be decomposed by heating them without oxygen at700C. This process is called pyrolysis. The products of this process are then recycled

into new products

Inventing biodegradable polymers: Such polymers should be mixed with substances thatcan be decomposed by bacteria (to become biodegradable) or light (to become

photodegradable) .


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GLASS AND CERAMIC

The major component of glass

a) is silica SiO2

b) glass is:

i.Transparent, hard but brittle.

ii.A heat and electric insulator.

iii.Resistant to corrosion.

iv.Chemical not reaction and therefore resistant to chemical attack.

v.Easy to maintain.

Type ,composition and uses of glass


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Ceramic

1) Ceramic are made from clay, for example kaolin ,a hydrated aluminiumsilicate , A12O3.2SiO2.2H2O.

2) When the clay is heated to a very high temperature they undergo a series of chemical reaction and are hardened permanently

to form ceramic

Properties and uses of ceramic

1) 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 temperature

c.Are heat and electric instrument

d.Are resistant to corrosion and wear

e.Are chemically not reactive

f.Do not readily deform under stress

2) 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 itemsi.To make pottery, china plates, and porcelain vases since they do not tarnis 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


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COMPOSITE MATERIAL

Mean of composite material

1)Composite material are made from two or more constituent material with significant different physical or chemical

properties and which remain separate and distinct within the finished structure

2)A composite material combines the advantages of strength of the two material without their weakness

Example composite material and it uses

REINFORCES CONCRETE

1.Concrete is hard, fireproof, waterproof, comparatively cheap and easy to maintain. It is more important construction materials.

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

SUPERCONDUCTOR1.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 the flow 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 amagnet.

Superconductor are used to build magnetically levitate high-speed train (atabout 552 km/h).

4. Superconductor are used to make chips for smaller and faster supercomputer.Superconductor also playan important role in high speed data processing in internetcommunication.


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FIBRE OPTIC1.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

FIBRE GLASS

1.Fibre glass is glass in the form of fine threads. Molten gas is dropped onto a refractory

rating disc when the glass flies off the disc glass to form fibre.

2.Fibre glass is strong than steel, do not burnt, stretch or rot, resistant to fire and water but

is brittle.

3.When fibre glass added to a plastic, a new composite material fibre glass reinforces

plastic is formed.

4.Fibre glass reinforces plastic has more superior properties than glass and plastic.

PHOTOCHROMIC GLASS

1.When 0.01 to 0.1% of silver chloride (a type of photochromic substances) and a smallamount of copper

(II) chloride are added to molten silicon dioxide, photochromic glassis formed.

2.The photochromic glass has a special properties. It darken when exposed to strong

sunlight or ultraviolet.

3.Photochromic glass is suitable for making sunglasses

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