Post on 16-Nov-2014
sulphuric acid is a diprotic (dibasic)
mineral acid which does not volatise.
In the pure, concentrated form, sulphuric acid is an
oily, colourless liquid which is dense and
viscous.
It has high boiling point, that is 270 ˚C
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
1
SULPHURIC ACID
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
2
USES OF SULPHURIC ACID
Figure 1:- Uses of Sulphuric Acid, H2SO4
sulphuric acid: making
fertiliser
superphosphate fertilisers :- - it is manufactured
from the reaction between sulphuric acid
and calcium phosphate.
Ammonia Sulphate fertiliser:- - It is manufactured by the neutralisation of sulphuric acid and
ammonia
Potassium Sulphate:- - It is
manufactured by the neutralisation of
sulphuric acid potassium hydoxide
2H2SO4 (l) + Ca3(PO4)2 (s) Ca(H2PO4)2 (l) + 2CaSO4 (s)
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
3
MANUFACTURE OF SULPHURIC ACID
The manufacture of sulphuric acid in industry is through the contact process.
The raw materials used to manufacture the acid are sulphur, air and water.
The acid is produced in 3 stages:-
2NH3(aq) + H2SO4(aq) (NH4)2SO4(aq)2KOH(aq) + H2SO4(aq) K2SO4(aq) + 2H2O (l)
Stage 3: Formation of sulphuric acid
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
4
STAGE 1:
THE PRODUCTION OF SULPHUR DIOXIDE
a) This can be obtained through two methods:-a) Heating liquid sulphur with hot air in a furnace.
S (s) + O2 (g) SO2 (g)b) Heating sulphides in air, for example:
4FeS2 (s) + 11O2 (g) 2Fe2O3 (s) + 8SO2 (g)
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
5
SO2 is a side-product in the extraction of the metal, iron. [Fe2O3 is reduced to iron with coke]Zinc pyrites can also be heated in air as follows:2ZnO (s) + 3O2 (g) 2SO2 (g) + 2ZnO (s)
STAGE 2:
FORMATION OF SULPHUR TRIOXIDE
a) Pure, dry sulphur dioxide is mixed with dry oxygen in excess and passed over vanadium(V) oxide, V2O5 as catalyst at a temperature of 450˚C - 550˚C and a pressure of 1 atmosphere. The conditions ensure the maximum production of sulphur trioxide:2SO2 (g) + O2 (g) 2SO3 (g)
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
6
b) The reaction takes place in a heat converter.c) Excess air is used to ensure higher percentage of SO3 produced.
STAGE 3:
FORMATION OF SULPHURIC ACID
a) The sulphur trioxide is dissolved in concentrated sulphuric acid to form a product called oleum, H2S2O7. This is carried out until the concentrated sulphuric acid has reached a concentration of 99.5%.SO3 (g) + H2SO4 (aq) H2S2O7 (l)
Sulphur
Sulphur dioxide SO2
Sulphur trioxide SO3
Oleum H2S2O7
concentated sulphuric acid, H2SO4
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
7
b) The product, oleum will not show any property of an acid. This is because, oleum will ‘not ionise’ without the presence of water.
c) Water is then added to the oleum to produce concentrated sulphuric acid.H2S2O7 (l) + H2O (l) 2H2SO4 (l)
d) The reaction in (a) and (b) is equivalent to dissolving sulphur trioxide in water.SO3 (g) + H2O (l) H2SO4 (aq)
e) However, this reaction is not carried out in industry. This is because the reaction is too vigorous.
f) It produces a large cloud of sulphuric acid mist. This mist is corrosive and pollutes the air.
CONTACT PROCESS:
Burnt in air
O2 , V2O5, 450˚C, 1 atm
Concentrated H2SO4
Water
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
8
Figure 2:- Flow chart of Contact Process
The
indu
stria
l pro
cess
in th
e M
anuf
actu
red
of S
ulph
uric
Aci
d
To manufacture nitrogenous
fertilisers
As a cooling agent
To prevent the coagulation of
latex in the rubber
industry
To manufacture nitric acid in industry
To manufactu
re explosive
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
9
USES OF AMMONIA IN INDUSTRY:
Examples are ammonium sulphate, ammonium nitrate and urea. The first two are prepare through neuralisation but urea is produced by the reaction of ammonia with carbon dioxide. The reaction involved are as the following: a) 2NH3 (g) + H2SO4 (aq) (NH4)2SO4 (s) ammonium sulphate b) NH3 (g) + HNO3 (aq) NH4NO3 (aq) ammonium nitrate c) 2NH3 (g) + CO2 (g) (NH2)2CO (s) + H2O (l) urea
Having a low melting point, liquefied ammonia makes a good cooling agent in refrigerators and air conditioners.
It neutralizes the organic acids formed by microorganisms in latex, thereby preventing coagulation and preserving the latex in liquid form.
Ammonia is converted to nitric acid in the Ostwald process:
1) ammonia is first oxidised to nitrogen monoxide, NO, by oxygen in the presence of platinum as catalyst at 900˚C.4NH3 (g) + 5O2 (g) Pt/900˚C 4NO (aq) + 6H2O (l)
2) nitrogen monoxide is further oxidised to nitrogen
The
indu
stria
l pro
cess
in th
e M
anuf
actu
red
of S
ulph
uric
Aci
d
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
10
EXPERIMENT TO INVESTIGATE THE PROPERTIES OF AMMONIA
Aim:-
To investigate the properties of ammonia
Material:-
0.1 mol dm ammonia solution, 0.1 mol dm sodium hydroxide solution, ammonia chloride, calcium hydroxide, concentrated hydrochloric acid, soda lime, distilled water, red litmus paper, Ph paper.
Apparatus:-
Ammonia is converted to nitric acid in the Ostwald process:
1) ammonia is first oxidised to nitrogen monoxide, NO, by oxygen in the presence of platinum as catalyst at 900˚C.4NH3 (g) + 5O2 (g) Pt/900˚C 4NO (aq) + 6H2O (l)
2) nitrogen monoxide is further oxidised to nitrogen
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
11
Test tubes, beaker, U-tube, Bunsen burner, glass rod, delivery tube, stoppers.
Procedure:-
a) Preparation of ammonia gas:1. Some ammonium chloride is mixed with some calcium
hydroxide.2. The apparatus as shown in Figure 3 is set up
3. The mixture is heated4. The ammonia gas produced is collected in a few test tubes.
The test tubes containing ammonia gas must be closed with stoppers.
b) Alkalinity of ammonia:1. 5.0 cm of 1 mol ammonia solution and 5 cm of 0.1 mol dm
sodium hydroxide solution are poured into two separate test tubes.
2. A piece of pH paper is dipped into the solution in each test tube.
3. The pH values of both solution are recorded.
c) Colour, physical state, smell and solubility of ammonia:
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
12
1. The colour and physical state of ammonia are observed.2. The stopper of a test tube containing ammonia gas is
removed and the smell of the gas is identified.3. A test tube containing ammonia gas is inverted into a beaker
of water.4. All observation are recorded.
d) Density of ammonia:1. A test tube containing ammonia gas is held upright and
another test rube containing ammonia gas is held upside down.
2. The stopper of the two test tubes are removed.3. After 20 seconds, a piece of moist red litmus paper is put at
the mouth of each test tube as shown in figure 5.4. The colour of the red litmus paper is recorded.
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
13
e) Chemical property of ammonia:1. One end of a glass rod is dipped into concentrated
hydrochloric acid.2. The glass rod is then put on top of a test tube of ammonia
gas.3. Any change taking place is observed.
Observation :-
Section Observation Inference
b)
pH of ammonia solution is 10
pH of sodium hydroxide solution is 14
ammonia is weak alkali
sodium hydroxide is a strong alkali
c)
colourless gas pungent smell water rushed up
and fills up the whole test tube
ammonia is a colourless gas with a pungent smell
ammonia is very soluble in water
d) moist red litmus paper on top of the upright test tube does not change colour.
Ammonia gas has escaped from the upright test tube and thus is slightly less dense than air
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
14
Moist red litmus paper under the inverted test tube turns blue
e) Dense white fumes are formed
Ammonia react with hydrogen chloride gas to form ammonium chloride
Discussion:-
Ammonia is a weak alkali and has a pH of 10 Ammonia is a colourless gas with a pungent smell Ammonia is very soluble in water, ionize partially in water to form
ammonium ions and hydroxideNH3 (g) + H2O (l) = NH4
+ (aq) + OH- (aq) Ammonia is slightly less dense than air Ammonia react with hydrogen chloride gas to form ammonium
chlorideNH3 (g) + HCl (g) = NH4Cl (s)
Conclusion:-
Ammonia is an alkaline, colourless gas with a pungent smell. It is very soluble in water and is less dense in than air. It react with
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
15
hydrogen chloride gas to form dense white fumes of ammonium chloride
HABER PROCESS
The gases are cooled down until condenses
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
16
The
man
ufac
ture
of a
mm
onia
thro
ugh
the
Hab
er P
roce
ss
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
17
PREPARATION OF AMMONIA FERTILISER
Aim:-
To prepare ammonium sulphate.
Material:-
1 mol dm-2 sulphuric acid, 2 mol dm-3 ammonia solution, methyl orange, filter paper
Apparatus:-
25.0 cm pipette, burette, conical flask, white tile, retort stand and clamp, beaker, glass rod, evaporating dish, filter funnel, Bunsen burner, tripod stand, wire gauze.
Procedure:-
The
man
ufac
ture
of a
mm
onia
thro
ugh
the
Hab
er P
roce
ss
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
18
a) Determining the volume of sulphuric acid that will neutralize 25.0 cm of ammonia solution:-
1. 25.0 cm of 2 mol dm-3 ammonia solution is transferred by a pipette to a clean conical flask.
2. Three drops of methyl orange indicator are added to the alkali. The solution turns yellow.
3. A clean burette is filled with 1 mol dm-2 sulphuric acid and clamped to a retort stand. The initial burette reading is recorded.
4. The conical flask with its content is placed on a white tile below the burette as shown in figure 6 below.
5. The sulphuric acid is added slowly into the conical flask. The conical flask is swirled gently throughout the titration.
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
19
6. The addition of sulphuric acid is stopped when the indicator changes from yellow to orange. The final burette reading is recorded.
7. The volume of acid needed to completely neutralize the 25.0 cm of 2 mol dm-3 ammonia solution is calculated. Let this volume V cm.
b) Preparation ammonium sulphate salt:-
1. 25.0 cm of 2 mol dm-3 ammonia solution is pipetted into a clean conical flask. No indicator is added.
2. V cm of 1 mol sulphuric acid is added from the burette to the ammonia solution.
3. The mixture in the conical flask is transferred to an evaporating dish and heated until a saturated solution is formed.
4. The hot, saturated salt solution is left to cool for crystallization to occur.
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
20
5. The crystal of ammonium sulphate formed are filtered, ashed and dried between sheets of filter paper.
Observation:-
A colourless solution is formed when sulphuric acid is added to ammonia solution.
The crystal obtained are white in colour
Discussion:-
The equation for the reaction is:H2SO4 (aq) + 2NH4OH (aq) (NH4)2SO4 (aq) + 2H2O (l)
Methyl orange is an acid-base indicator used to determine the end point of the titration.
The first titration is carried out to determine the exact volume of sulphuric acid required to completely neutralize the 25.0 cm of ammonia solution.
The salt solution in the first titration is discarded because it is contaminated by methyl orange.
The ammonium sulphate solution should not be heated until dryness because ammonium sulphate decomposes when it is overheated.
The weight of ammonium sulphate obtained from the activity is always less than the theorical value. This is because some of the salt is not fully crystallized out and still remains in the solution.
Other ammonium salt such as ammonium nitrate can be prepared from the reaction between nitric acid and ammonium solution.
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
21
Conclusion:-
Ammonium sulphate and other ammonium fertilizers can be prepared by neutralizing ammonia solution with the respective acids.
THE PHYSICAL PROPERTIES OF PURE METAL
THE PHYSICAL PROPERTIES OF
PURE METAL
Ductile
Malleable
High Density
Good Conductor
High Melting & Boiling
point
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
22
PROPERTIES OF AMMONIA
alkaline gas, colurless
and pungent gas
Ammonia turns the damp red litmus paper blue.
The gas is less dense than air
NH3 + H2O NH4+ OH-
Aqueous solutions of ammonia react with metal ions (except Na+, K+, and Ca2+) to produce precipitate of metal hydroxide
Ammonia is weak alkali which reacts with dilute acids in neutralization to produce salt.
2NH3 + H2SO4 (NH4)2SO4 Ammonia gas burns in oxygen to produce nitrogen monoxide gas
4NH3 + 5O2 4NO + 6H2O
An inverted filter funnel is used to prevent sucking back of water
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
23
ALLOY
Meaning and purpose of making alloy:-
Alloying is a process of mixing two or more metals (or mixing metals with element such carbon) which cannot be separated using physical way
Arrangement of atoms in alloys:-
Pure metal A Pure metal B
Alloys
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
24
COMPARE THE HARDNESS OF A PURE METAL AND ITS ALLOYS
Aim:-
To compare the hardness of a pure metal and its alloy.
Problem Statement:-
Are alloys harder than pure metal ?
Hypothesis:-
Bronze is harder than cooper.
Variables:-
Manipulated: Different types of materials (cooper & bronze) Responding: diameter of the dent Controlled: diameter of steel ball bearing, height of the weight,
mass of the weight.
Operational definition:-
1) If the diameter of the dent is smaller, then the material is harder
Materials:-
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
25
2) Cooper block, bronze block, cellophane tape
Apparatus:-
3) Retort stand and clamp, 1-kg weight, metre ruler, steel ball bearing, thread.
Procedure:-
1) A steel ball bearing is taped onto a cooper block using cellophane tape.
2) A 1-kg weight is hung at a height of 50 cm above the cooper block as shown in the figure 8.
3) The weight is allowed to drop onto the ball bearing.4) The diameter of the dent made by the ball bearing on the cooper
block is measured.5) Steps 1-4 are repeated twice on the other parts of the cooper
block in order to obtain an average value for the diameter of dents formed.
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
26
6) Steps 1-5 are repeated using a bronze block to replace the cooper block.
7) The reading are recorded in the table.
Results:-
METALDIAMETER OF THE DENT (mm)
1 2 3 averageCooper 2.9 2.8 2.9 2.9
Bronze 2.1 2.2 2.2 2.2
Discussion:-
1) The smaller the diameter of the dent, the harder and stronger is the material.
2) The average diameter of the dent made on the surface on the cooper block is bigger than the bronze block.
3) Based on the result, bronze is harder than cooper.
Conclusion:-
The hypothesis is accepted.
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
27
EXAMPLE OF ALLOYS
EXAMPLE OF ALLOY
Brass
Stainless Steel
Manganese steel
Manganese Steel
Bronze
Stainless steel
steel
Pewter
Bronze
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
28
THE RATE OF RUSTING OF IRON, STEEL, AND STAINLESS STEEL
Aim:-
To compare the rate of rusting of iron, steel and stainless steel.
Problem statement:-
How does the rate of rusting of iron, steel and stainless steel differ?
Hypothesis:-
Iron rust faster than steel, and steel rust faster than stainless steel.
Variables:-
Manipulated variable: Different types of nails Responding variable: Intensity & amount of blue colour Controlled variable: Size of nails, concentration of solution used,
durations for rusting.
Operational definition:-
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
29
The more intense the blue colour formed, the higher is the rate of rusting.
Materials:-
Iron nail, steel nail, stainless steel nail, jelly solution, potassium hexacyanoferrate(lll) solution, water, sandpaper.
Apparatus:-
Test tubes, test tube rack.
Procedure:-
1) The nails are rubbed using sandpaper to remove the rust from the surface of the nails.
2) The iron nail placed in the test tube A, the steel nail in test tube B and the stainless steel nail in test tube C.
3) A 5% jelly solution is prepared by adding 5 g of jelly into 100 cm of boiling water. A few drops of potassium hexacyanoferrate(lll) solution are then added to the jelly solution.
4) The hot jelly solution is poured into the three test tubes until all the nails are fully immersed.
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
30
5) The test tubes are placed in a test tube rack and left aside for three days. The intensity of the blue colour is observed.
6) All observation are recorded in the table.
Observation:-
Test tube Intensity of blue colour InferenceA Very High Rusting occurs very fastB Low Rusting occurs slowlyC Nil No rusting occurs
Discussion:-
1) When iron rust, each iron atom loses two electrons to form an iron(ll) ion, Fe2+.Fe (s) = Fe2+ (aq) + 2e- (aq)
2) Potassium hexacyanoferrate(lll) solution is added to the jelly solution as an indicator to detect iron(ll) ions.
3) When there is iron(ll) ion, potassium hexacyanoferrate(lll) solution will form dark blue colouration.
4) The higher the intensity of the blue colour, the higher is the rate of rusting.
5) Solidified jelly solution is used to trap and see the blue colouration clearly. This is because diffusions occurs the slowest in solids.
6) Based on the observation, iron rust faster than steel. Stainless steel does not rust.
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
31
7) The nail made from stainless steel does not rust. This is because this nail is an alloy of iron with carbon, chromium and nickel.
8) The nail made from steel will rust slowly. The presence of carbon atoms will make the steel stronger than iron but does not prevent it from rusting.
9) Rusting of iron is an example of corrosion. When corrosion occurs, the metal loses electrons to form metal iron.
Conclusion:-
Iron rust faster than steel. Stainless steel does not rust. Hypothesis is accepted.
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
32
COMPOSITONS OF ALLOYS & THEIR USES
Alloy Composition Properties UsesCupronickel
Cu 75%Ni 25%
Hard, strong, resist corrosion
Coins
DuraluminAl 95%Cu 4%Mg 1%
Light, strongAeroplane part, electric cables racing bicycles
SteelFe 99%
C 1%Hard, strong, cheap
Vehicles, bridges, buildings
Stainless steel
Fe 73%Cr 18%Ni 8%C 1%
Hard, rust resistant
Kitchen appliance, watches, knifes, fork, spoons, machine parts
bronzeCu 90%Sn 10%
Hard, strong, shining
Decorative items, medals, artwork, pots & pans
BrassCu 70%Zn 30%
Harder and cheaper than Cu
Musical instrument, bell, nails, screw, and pots
SolderPb 50%Sn 50%
Low melting point, strong
Welding, soldering work
PewterSn 91%Sb 7%Cu 2%
Malleable, ductile, rust resistant
Decorative items,souvenirs
MagnaliumAl 70%
Mg 30%Light, strong
Tyre rim of racing car, skeletal body of aeroplane
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
33
POLYMER
POLYMER
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
34
NATURAL POLYMER
Natural polymer
Protein Carbohydrates Natural Rubber
Monomer acid amino
Eg: in muscle, skin, silk, hairs, wools, and furs
Monomer glucose Eg: in starch and
cellulose
Monomer isoprene(2-methylbuta-1,3 diene)
Eg: in latex
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
35
SYNTHETIC POLYMER & IT USES Synthetic polymers are polymers made in industry from chemical
substances. Many of the raw materials for synthetic polymers are obtained from
petroleum, after refining and cracking process.
Synthetic rubberStyrene- butadlene rubber (SBR) (monomers: styrene &
butadlene.eg:- shoe soles & tyres
Neoprene (monomers: chloroprene)eg:- gloves, electric wire insulator, water pipes
Butyl rubber (monomers: isobutylene & isoprene)eg:- inner tubing of tyre, hoses, shoe soles
Perspex (monomers: methyl metacrylate)eg:- spectacles, car lamps
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
36
WHY USE SYNTETIC POLYMERS IN DAILY LIFE?
Synthetic polymers
Strong & light
can be made to have special
properties
cheapable to resist corrosion
easily moulded or shaped & be coloured
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
37
ENVIRONMENTAL POLLUTION RESULTING FROM THE DISPOSAL OF
SYNTHETIC POLYMERS
Effects of improper Disposal of
Synthetic Polymer
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
38
GLASSGlass:-
The major component of glass is silica or silicon dioxide, SiO2 which found in sand.ri
Properties of glass
Impermeable to liquid
Electrical insulator
Heat insulator
Chemically inert
hard but brittle
Transparent
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
39
TYPES, COMPOSITION, PROPERTIES, AND USES OF GLASS
GLASS COMPOSITION PROPERTIES USES
Soda lime glass
SiO2 – 70%Na2O – 15%CaO – 10%
Others – 4%
Low melting point Mouldable into shapes Cheap Breakable Can withstand high
heat
Glass container Glass panes Mirror Lamps and bulbs Plates and bowls Bottles
Lead glass (crystal)SiO2 – 70%Na2O – 20%PbO – 10%
High density and refractive index
Glittering surface Soft Low melting point
(600˚C)
Containers for drinks and food
Decorative glass Crystal glassware Lens for spectacles
Borosilicate glass (Pyrex)
SiO2 – 80%B2O3 – 13%Na2O – 4%Al2O3 – 2%
Resistant to high heat &chemical reaction
Does not break easily Allow infra-red rays
but no ultra-violet rays
Glass apparatus in lab Cooking utensils
Fused silicate glassSiO2 – 99%B2O3 – 1%
High melting point (1700˚C)
Expensive Allow ultraviolet to
pass through Difficult to melt or
mould into shape
Scientific apparatus like lens on spectrometer
Optical lens Lab apparatus
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
40
CERAMICSCeramics:-
Ceramic is manufactured substances made from clay that is dried, and heated in a kiln at a very high temperature
The main component of clay is aluminosilicate (aluminum oxide and silicon dioxide) with small quantities of sand and feldspar. Unlike glass, ceramic cannot be recycled.
Kaolinite is a high quality white clay that contains hydrated aluminosilicate, Al2O3•2SiO2•2H2O.
Properties of ceramics
extremely hard & strong
but brittle
has a very high melting
point
inert to chemicals
good insulator of electricity
and heat
able to withstand and
resist corrosion
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
41
THE DIFFERENT CLASES OF CERAMIC
GROUP COMPOSITIONMineral Quartz – SiO2
Calcite – CaCO3
Cement material Mixture of CaSiO3 and ammonium silicateOxide of ceramic Aluminium oxide – Al2O3
Silicon dioxide – SiO2
Magnesium oxide – MgO Non-oxides of ceramic Silicon nitride – Si3N4
Silicon carbide – SiC Boron nitride – BNBoron carbide – B4C3
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
42
THE USES OF IMPROVED GLASS AND CERAMICS FOR SPECIFIC PURPOSES
GLASS OPTICAL FIBREA pure silica glass thread that conducts light.this fibres can transmit messages modulated onto light waves.used inmedical instrument, LAN
CONDUCTING GLASSa type of glass that can conduct electricity.produce by embedding a thin layer of conducting material in glass.adding a layer of indium tin(iv) oxide (ITO) acts as an electrical conductor.used in the making of LCD
GLASS-CERAMICRearrange its atoms into regular patterns by heating glass to form strong materialit can withstand high temperature, chemical attacksused in tile, cookware, rockets, engine blocks
CERAMIC SUPERCONUCTORsuperconductor can conduct electricity at low temoerature without resistance, loss of electrical energy as heatused to make light magnet, electric motors, electrical generators
PHOTOCHROMIC GLASSsensitive to light intensitythe glass darken when exposed to sunlight but became clear when light intensity decresase.used in windows, sunglasses ad instrument control
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
43
COMPOSITE MATERIALS A composite material is structural material formed by
combining two or more materials with different physical properties, producing a complex mixture.
They are used to make various substances in daily life because of the following reasons:-
a) Metals corrode and are ductile and malleableb) Glass and ceramic break easilyc) Metal are good conductors but have high resistant,
leading to loss of electrical energy as heat.d) Plastic and glass can withstand heat to a certain level
only
Hafiz AkmalCHEMISTRY FOLIO chapter 9: Manufacture Substances in industry
44
COMPOSITE MATERIAL
COMPONENT PROPERTIES OF COMPONENT
PROPERTIES OF COMPOSITE
USES
Reinforced concrete
concrete hard but brittle low tensile strengh
stronger higher tensile strength does not corrode
easily cheaper can be moulded into
shape can withstand very
high applied force can support very
heavy load
construction of road rocket launching pads high-rise buildings
steel strong in tensile strength
expensive can corrode
Superconductor
Cooper(ll) oxide Yttrium oxide Barium oxide
Insulator of electricity
Conducts electricity without resistance when cooled by liquid nitrogen
Magnetically levitated train
Transformer Electric cable Computer parts
Photochromic glass
Glass Transparent Not sensitive to
light
Reduce refraction of light
Control the amount of light passed through it auto.
Has the ability to change colour and become darker when exposed to ultraviolet light
Information display panels
Light detector device Car windshields Optical lens
Silver chloride or silver bromide
Sensitive to light
Fibre optics
Glass with low refraction index
Transparent Does not reflect
light rays
Low material cost Reflect light rays and
allow to travel along the fibre
Can transmit electronic data or signal, voice and image
Transmit data using light waves in telecommunications
Glass with higher refractive index
Fibre glass
glass high density strong but brittle non-flexible
high tensile strength moulded and shaped inert to chemicals light, strong, tough non-flammable impermeable to water resilient flexible
car bodies helmets skies rackets furniture polyester plastic light
flexible inflammable elastic but weak