1. 1. IIT-JEE Syllabus
Commercially important ores of iron, copper, lead, magnesium, aluminium , tin and
silver . Carbon reduction process (iron and tin), Self reduction process (copper and
lead), Electrolytic reduction process (magnesium and aluminium), Cyanide process
(silver and gold).
2. Introduction
The earth’s crust is the main source of metals. The occurrence of metal in native or in
combined state in the earth’s crust along with a number of rocky and other impurities
depends upon the chemical nature of metals. Metals having less electropositive character
have less affinity for oxygen, moisture and occur in free or metallic or native state i.e., in
uncombined state e.g. Au, Pt , Ag etc. On the other hand metals with higher electropositive
character occurs in combined state i.e., as compounds.
The compound of a metal found in nature is called a mineral. A mineral may be a single
compound or a complex mixture. Those minerals from which metal can be economically
extracted are called ores. Thus all ores are minerals but all mineral are not ores. For e.g.
copper occurs in nature in the form of several minerals like Cu2O, Cu2S, CuFeS2, but copper
pyrites is considered as the most economical mineral for the extraction of the metal. Hence
copper pyrites is the chief ore of copper.
Ores may be divided into four groups
i) Native Ores: These ores contain the metal in free state eg. Silver gold etc. These are
usually formed in the company of rock or alluvial impurities like clay, sand etc.
ii) Oxidised Ores: These ores consist of oxides or oxysalts (eg. carbonates, phosphate)
and silicate of metal. Important oxide ore includes, Fe2O3, Al2O3.2H2O etc. and important
cabonate ores are limestone (CaCO3), Calamine (ZnCO3) etc.
iii) Sulphurised Ores: These ores consist of sulfides of metals like iron, lead, mercury etc.
Examples are iron pyrites (FeS2). galena (PbS), Cinnabar (HgS)
iv) Halide ores: Metallic halides very few in nature. Chlorides are most common examples
include horn silver (AgCl) carnallite KCl. MgCl2.6H2O and fluorspar (CaF2) etc.
3. Metallurgy
It is the branch of engineering employed for
the extraction of metals economically on a
large scale from their respective ores. Before
going into the description of extraction
process we should study at least the
Ellingham diagram regarding the stability of
different oxides.
300 600 900
– 1200
– 1000
– 800
– 400
– 300
0
1000
Temperature (C)
Cu
Change
in
Gibbs
free
energy
(G
0
)
kJ
mole
–
Mg
Al
C
Fe
Hg
Ag

2. Less the G0
value i.e. more the G0
is negative more will be the stability of that oxide. It is
clearly observed from the diagram G0
for the reaction C + CO
O
2
1
2 
 is always
negative after 800C.
Thus for Zn + ZnO
O
2
1
2 
 …(1)
And C+ CO
O
2
1
2 
 …(2)
The reduction of ZnO to Zn will be spontaneous at higher temperature.
0
ZnO
0
CO G
G 

 = – 57 – (–42) = – 15 kcal / mole
G0
= negative, so the reduction of ZnO by coke is spontaneous at 1200C. This is why in
all the carbon reduction process the temperature is very high called as pryometallurgy. But
at 25C G0
CO – G0
ZnO = – 33 – (–76) = + 43 kcal/mole. So, no reactants, Hg, Ag crosses
G0
= 0 line at higher temperature. Thus on heating HgO  Hg +
2
1
O2
or Ag2O  2Ag +
2
1
O2 conversion takes place.
The eligibility of metal as reducing agent in reduction of other metal oxides can be
deciphered from this diagram. Carbon line slopes downward at around 710C. Hence C can
be used as a reducing agent at higher temperature. The graph shows the temperature when
the oxide line cuts the C-line. This is the temperature of reduction of the oxide by C. Thus
MgO is reduced at 1650C, ZnO at 950C, FeO at 725C.
Certain melting processes
C – reduction process: Fe2O3 + C  Fe3O4 + CO
Fe3O4 + C  FeO + CO
FeO + C  Fe + CO
ZnO + C  Zn + CO etc
Self reduction process
Cu2O + Cu2S  Cu + SO2
For carbonate ores
ZnCO3  ZnO + CO2
ZnO + C  Zn + CO
Hydrometallurgy: By this technique at normal temperature the metal can be extracted.
For example: Ag, Au are precipitated by this preparation.
2Na[Ag(CN)2] (aq) + Zn(s)  Na2[Zn(CN)4] + 2Ag
2Na [Au(CN)2] aq. + Zn(s)  Na2[Zn(CN)4] + 2Au

3. Electrolytic Reduction: This is applied for the active metal cloride or Al2O3
MX  M+
+ X–
At cathodeM+
+ e M
At anode X–
– e  X
2X  X2
Amalgam: These are prepared by treating metals like Sn, Zn, Au, Na, Ag etc. with Ag.
Uses: 1. Na/Hg decreases the reactivity of Na
2. Sn/Ag are used in filling
Some important alloys and uses are as follows
Brass Cu (60 – 80), Zn (40 –20 Utensils
Bell metal Cu (80), Zn (20) Bells
Bronze Cu (70 –90), Zn (10 – 30) Statues, coins
German silver (Cu – 50, Zn – 25, Ni – 25) Resistance coils, ornaments
Monel metal (Cu – 30, Fe, Mn – 3, Ni – 57) Acid containers
Aluminium Bronze (Cu 90, Al 10) Ornaments
Gun metal (Cu 87, Sn 19, Zn – 3) Gears
Duralmin (Al 95, Cu 4, Mg 5, An 5) Automobiles parts
Magnelium (Al 98, Mg 2) Light
Type metal (Pb – 75, Sb – 20, Zn – 5) Printer
Common solder (Pb – 50, Sn – 50) Soldering
Stainless steel (Cr (14-18), N(7-9),
Fe(73-79)
Utensils
Electron (Mg – 95, Zn 4.5, Cu – 0.5) Automobiles parts
Constantine (Cu – 60, Ni – 40) Electrical apparatus
Pewter (Pb – 25, Sn – 75) Water reservoir
Illustration 1: Write short notes on
(a) Amalgamation (b) Hydrometallurgy
(c) Self reduction (d) Electrolytic reduction
Solution: a) This process is used for the extractioin of noble metals like gold and
silver from the native ores. The finely crushed ore is brought into
contact with mercury which combines with the metal forming its
amalgam. The metal is then recovered by distilling the amalgam.
b) Hydrometallurgy is the process of bringing the metal into solution by
the action of suitable chemical reagents (e..g., sodium cyanide

4. solution or chlorine in presence of water etc.) followed by recovery of
the metal by the use of a proper precipitating agent which is a more
electropositive metal. For example, poor ores of silver are suspended
in a dilute solution of sodium cyanide and air is blown through it when
the silver present goes into solution as the argentocyanide complex.
From this solution the metal is precipitated by adding zinc turnigs.
4Ag + 8NaCN + O2 (air) + 2H2O  4Na [Ag(CN)2] + 4NaOH
or AgCl + 2NaCN  Na[Ag(CN)2] + NaCl
2Na [Ag(CN)2] + Zn  Na2[Zn(CN)4] + 2Ag
c) In some cases no extra reducing agent is required. A part of the
sulphide ore is changed to oxide or sulphate which then reacts with
the remaining part to give the metal and sulphur dioxide. Copper and
lead are obtained by this method.
2Cu2S + 3O2  2Cu2O + 2SO2
Cu2S + 2Cu2O  6Cu + SO2
2PbS + 3O2  2PbO + 2SO2
PbS + 2O2  PbSO4
PbSO4 + PbS  2Pb + 2SO2
d) The carbon reduction methods are not applicable for the highly
electropositive and chemically active metals such as alkali metals,
alkaline earth metals, aluminium etc. The oxides of these metals are
very stable and have to be heated very strongly with carbon in order
to reduce them to metals. But at high temperatures these metals
combine with carbon to form carbides, thus creating problem. Hence
these metals are extracted by the electrolytic reduction of their fused
halides. The metal is liberated at the cathode. Aluminium is however
obtained by the electrolytic reduction of alumina (Al2O3) dissolved in
molten cryolite (Na3AlF6).
3.1 Refining or purification
The metals obtained by the application of above reduction methods from the concentration
ores are usually impure. The impure metal is thus subjected to some purifying process
known as refining in order to remove undesired impurities. Various process for this are
a) Liquation process b) Distillation process
c) Cupellation d) Polling
e) Elecrolytic refining f) Bessemerisation
Bassemerisation: This is a process in the metallurgy of copper. It involves the reduction of
molten matte (mixture of cuprous and ferrous sulphide) obtained after smelting of copper
pyrites ore in a Bessemer converter.

5. The molten matte is taken in Bessemer converter and heated by blowing hot blast of air and
sand through tuyeres. The following reactions takes place in the converter.
i) Air oxidizes iron sulphide to iron oxide and SO2
2FeS + 3O2  2FeO + 2SO2
ii) Sand reacts with iron oxide to form iron silicate
2FeO + SiO2  FeSiO3 (Slag)
iii) After the iron has been removed, hot blast of air converts a part of cuprous sulphide to
cuprous oxide.
2Cu2S + 3O2  2Cu2O + 2SO2
iv) The cuprous oxide so formed reacts immediately with remaining cuprous sulphide to
form metallic copper.
Cu2O + Cu2S  6Cu + SO2
Since the reaction is exothermic, the heat liberated maintains the crude copper in the
molten state. The completion of the reaction is indicated by the appearance of green
flame produced by the vaporization of copper.
Exercise 1: What is solvent extraction
Exercise 3: What is the main differences between cupellation and poling?
3.2 Furnaces
It is a device in which high temperature is produced either by burning a fuel or by using
electricity. The important ones are described below.
a) Blast Furnace: It is used for smelting iron, copper and lead ores. It has a tall structure
made of steel plates rivetted together lined inside with fire bricks. The furnace is
provided with an arrangement for blowing air near the base, a slag hole, a tapping hole
for removing the molten metal and an exit for waste gases near the top. The charge is
introduced at the top. The mouth of the furnace is closed by a special arrangement
through which the charge is introduced.
b) Reverberatory Furnace: It is used for calcination, roasting or for smelting. The charge
in the powdered form along with a flux is placed on the hearth of the furnace. The fuel is
placed on grate and the flames are deflected from its low sloping roof. This furnace is
used in case of copper, tin, lead and wrought iron.
c) Muffle Furnace: A furnace in which the charge container is heated from all sides is
called muffle furnace. The burnt materials including the vapours of the metal are allowed
to escape through the same opening. The metal is obtained by condensing the vapours.
In Belgian process for extracting zinc, the retorts act as muffles and prolongs help in
completing the condensation.
d) Bassemer Converter: It is a pear-shaped furnace made of steel plates lined inside with
lime or magnesium oxide. It is fixed on pivots and can be tilted in any direction. It is
provided with pipes through which hot air can be blown for heating purposes.

6. Exercise 3: What is Goldsmidt Thermite Process:?
Exercise 4: Explain the following terms
i) Zone refining (Fractional crystallization)
ii) Electro-refining
iii) Van-Arkel Method
4. Extraction of Aluminium
4.1 Important ores of Aluminium
Aluminium: [13Al127
, electronegativity 1.5, 1s2
2s2
sp6
3s2
3p]
Ores
i) Corundum (Al2O3)
ii) Bauxite (Al2O3.2H2O), Gibbsite (Al2O3.3H2O) Diaspore (Al2O3.H2O)
iii) Cryolite (AlF3.3NaF)
iv) Alunite [K2SO4.Al2(SO4)3.4Al(OH)3]
v) Spinel MgO.Al2O3
vi) Felsper (K2O.Al2O3.6SiO3)
vii) China Clay or Kaoline [Al2O3.2SiO2.2H2O]
Extraction
Purification of Bauxite: By Bayer’s process comercially it is being carried out (for red
bauxite not for the white bauxite).
Flow sheet of Bayer’s process for the preparation of pure Al2O3
Finely powdered bauxite
containing Fe2O3, TiO2.SiO2
as impurities
Calcined ore
Residue
(Fe2O3, TiO2)
Filtrate
(NaAlO2 + Na2SiO3)
Calcination (FeO  Fe2O3)
Organic matters are removed
(Digested with 45%, NaOH with
at 150C under 80 lb pr. Filtered)
Al2O3 Pure
Alumina
Precipitate
(Al(OH)3
Filtrate
(NaOH, Na2SiO3)
1000C
Freshly prepared Al(OH)3 as seeding agent filtered

7. Hall’s process: Crude bauxite at 1100C reacts with Na2CO3, little CaCO3 when CaSiO3,
NaSiO2, NaFeO2 etc. from
Al2O3 + Na2CO3  2NaAlO2 + CO2
Fe2O3 + Na2CO3  2NaFeO2 + CO2
SiO2 + Na2CO3  Na2SiO3 + CO2
CaO + SiO2  CaSiO3
Then at 50 – 60C CO2is formed through NaAlO2 solution and produces thereby Al(OH)3
2NaAlO2 + CO2 + 2H2O  2Al(OH)3 + Na2CO3
Al(OH)3 

 
 C
100
Al2O3 + 3H2O
Serpeck’s Process
Al2O3 + 3C + N2  3AlN + 3CO
SiO2 + 2C  Si + 2CO
AlN +NaOH  NaAlO2 + NH3
NaAlO2 + 2H2O  Al(OH)3 + NaOH
AlN + 3H2O  Al(OH)3 + NH3
2Al(OH)3
)
cryolite
(
2
3
2
C
1100
O
H
3
O
Al 


 


Electrolytic reduction of Al2O3: At 900C, AlF3.3NaF, CaF2 (Fluorspar) to make Al2O3 a
good conductor of electricity. Metallic Al is liberated at the cathode
Electrolysis of molten mixture
Cathode : Carbon
Anode : Graphite rods
Electrolyte : 60 parts cryolite + 2O parts fluorospar + 2O parts pure Al2O3
Temperature : 900C
Reactions
According to the 1st
theory the following reaction occurs
Al2O3 2Al+3
+ 3O–2
At cathode: 2Al+3
+ 6e  2Al
At anode : 3O–2
– 6e 3O2
As cryolyte has greater electrochemical stability it does not dissociate. It only increases the
dissociation of Al2O3
But the second theory states that, cryolite undergoes electrolytic dissociation first then Al+3
goes to the cathode, produced F2 at anode then reacts with Al2O3 produces AlF3.
AlF3.3NaF Al+3
+ 3Na+
+ 6F–

8. At cathode: Al+3
+ 3e  Al
At anode : 6F–
– 6e  3F2
Al2O3 + 6F2  4AlF3 + 3O2
Properties of Al
Physical Properties: Al is silver white, light metal having sp gravity, 2.7. It is very soft,
malleable and ductile. Al is a good conductor of heat and electricity.
Chemical Properties
1. With air aluminium oxide aluminium from with bright white flame.
4Al + 3O2  2Al2O3
2Al + N2  2AlN
2. By thermit process Al reduces Fe, Cr etc., from their stable oxides (refer to the Ellingham
diagram)
At 1900C. Al combines with O2 of Cr2O3, Fe2O3 and reduces consequently to Cr, Al.
Exothermictiy of the reactions increases the temperature of the molten pool
3000 – 3500C
The reactions are
4Al + 3O2  2Al2O3 + 772 kcal
2Al + Fe2O3  Al2O3 + 2Cr + 199 kcal
2Al + Cr2O3  Al2O3 + 2Cr + 131 kcal
Arrangement is like the following diagram; Ignition mixture (KClO3 + Mg powder)
Mg-ribbon
Fire proof crusible
Molten Fe droplets
Broken iron rail
Fire clay
Fe2O3 +Al produce
3. Al powder reacts with boiling water (not water at ordinary temp) and produce Al(OH)3.
2Al + 6H2O  2Al(OH)3 + 3H2
4. Action with acids and alkalis both are as follows
2Al + 6H2O  Al2(SO4)3 + 3SO2 + 6H2O
The partial reactions are as the following
[H2SO4  H2O + SO2 + O]  3

9. 2Al + 3O  Al2O3
Al2O3 + H2SO4  Al2(SO4)3 + 3H2O
––––––––––––––––––––––––––––––––––
2Al + 6H2SO4  Al2(SO4)3 + 3SO2 + 2H2O
2Al + 2NaOH + 2H2O 
 
heat
2NaAlO2 + 3H2
2Al + Na2CO3 + 3H2O  2NaAlO2 + CO2 3H2O
There is no action of dil. Or conc. HNO3; Conc. HNO3 however makes Al provine by the
formation of. This oxide film.
2Al + N2  AlN
2Al + 3Cl2  2AlCl3
4Al + 3O2  2Al2O3
2Al + 3S  Al2S3 etc.
AlN + H2O  Al(OH)3 + NH3
AlCl3 + 6H2O 
.
ppt
white
3
)
OH
(
Al  + 3(H+
+ Cl–
)
Al2S3 + 6H2O  2Al(OH)3 + 3H2S (Oboxions odour)
6. Al + CuSO4  Al2(SO4)3 + Cu
This displacement reaction is because of 0
Cu
/
Cu
0
Al
/
Al 2
3 E
E 
 
Uses of Al
1. As wires for electrical transmission
2. As deoxidiser in steel making etc.
Some of the important alloys of Al are gives in the following table
Alloy Composition Uses
Magnesium Al (98%), Mg(2%) Reactive parts
Duralium Al (95%), Cu(4%) Air Craft Parts
Aluminium Bronze Al10%), Cu(90%) Utensils
Alnico Al(20%), N(20%), Co(10%), Steel
(50%)
Permanent magnets
-alloy Al 92%, Cu 4%, Mg 1.5%, Ni 2.5%
Nickel alloy Al 95%, Cu 4%, Ni 1% Aircrafts parts
Anodizing & Calorising: Al2O3 coating on aluminium its alloys to save from the corrosion.
The article to be coated is taken as anode after cleaning chromic acid bath is used. On
passage of electricity it gives Al2O3 coating. Decorative coating is given to the articles.

10. Calorising is the process of impregnation of the surface of Fe, steel, copper, nickel etc.
Withmetallic Al, This is done by heating at 1000C with fine powder of takes place causing
the good adherent bond. Calorised Ni brass etc., are resistant to acids to oxidation at high
temperature.
5. Extraction of Iron
5.1 Important Ores of Iron
Ores
Magnetite (Fe3O4)
Red haematite (Fe2O3)
Brown haematic (Fe2O3.3H2O)
Or Limonite
Spathic iron or sidirite (FeCO3)
Iron pyrites (FeS2), Copper pyrites (CuFeS2)
5.2 Extraction of Cast Iron
1. Dressing of the ores: The iron ores are first broken into small pieces 3-5 cm in size.
2. Roasting or Calcination: During roasting S, As, P are oxidised to the respective oxides.
S + O2  SO2
4As + 3O2  2As2O3
FeCO3 decomposes as,
FeCO3  FeO + CO2
Fe2O3.3H2O loses water
Fe2O3.3H2O  Fe2O3 + 3H2O
Fe3O4 is decomposed to ferrous oxide and ferric oxides.
Fe3O4  FeO + Fe2O3
Ferrous oxide reacts with silica to forms ferrous silicate at high temperature.
FeO + SiO2  FeSiO3
But the conversion of FeO into Fe2O3 will prevent the formation of FeSiO3,. Thus the
mass of the ore becomes porous casting the increase in the effective surface area.
3. Smelting in the Blast furnace: Blast furnace is a shaft furnace made of steel plate of
20-30 in with 4 – 4.6 diameter.
5.3 Extraction of Cast Iron
Iron is usually extracted from the haematite. Concentrated ore after calcination is reduced
with carbon i.e. smelted in the blast furnace.

11. Reactions taking place in the blast furnace
i) Zone of combustion
2
2
)
Coke
(
CO
O
C 


ii) Zone of reduction
Fe2O3 + 3CO  Fe + CO2
iii) Zone of reduction
Fe2O3 + 3CO  2Fe + 3CO2
FeO + CO  Fe + CO2
iv) Zone of slag formation
2
)
stone
e
(lim
3 CO
CaO
CaCO 


slag
Fusible
3
2 CaSiO
SiO
CaO 

 ;
v) Zone of fusion lower part of furnace
Charge
Cup and cone
arrangement
Waste gases
Refractory bricks
Hot air
Tuyeres
Molten metal
Molten slag
200–250C
400C
600C
700C
800–1000C
1300C
1600C
Blast furnace
Molten iron is heavier from molten slag. The two liquids are periodically tapped off. The molten
iron tapped off from the furnace is solidifed into blocks called ‘pigs’.
5.4 Preparation of Wrought Iron
This is done by heating cast iron with haematite (Fe2O3) which oxidises C to CO, S to SO2,
Si to SiO2, P to P4O10 & Mn to MnO
Fe2O3 + 3C  2Fe + 3CO
Where CO & SO2 escape, manganous oxide (MnO) and Silica (SiO2) combine to form slag.
MnO + SiO2  MnSiO3
Similarly phosphorus pentoxide combines with haematite to form ferric phosphate slag.
2Fe2O3 + P4O10  4FePO4
Illustration 3: Cast iron is hard but pure iron is soft in nature. Explain why?
Solution: Cast iron contains 2.5 to 5% carbon which makes cast iron hard.
Bosh: The diameter of the furnace gradually increases from the top down wards. Widest
part of the furnace is called Bosh. At above 2 m. tuyeres are there through which hot air
blast is blown into the furnace.
Hearth: Below the bosh this region exists. (1) slag notch is at higher height and (2) tap hole
for metal passage at lower position from the bottom. At the top of the furnace the hopper is
there which is cup and cone arrangement. Through this charge is introduced till the charge
bed in the furnance is 4/5th the of the furnace. Hot air at 700C is forced into the furnace

12. through the tuyeres. The thermal gradient inside exists from 1800C (hearth) to 400C –
900C in the upper region. Near the bogh the temperature varies from 1200C – 1300C
chemical reactions which take place are.
1. At 1200C near the tuyeres,
C + O2  CO2; CO2 + C  2CO
2. Above bosh 600 – 900C, ferric oxide is partially reduced by CO as
Fe2O3 + 3CO 2Fe + 3CO2
3. CaCO3 

 
 C
900
CaO + CO2
2CO 



 
  C
1300
1000 
CO2 + C
Fe2O3+ 3C  2Fe + 3CO
CaO + SiO2  CaSiO3 (slag)
4. The reaction at 1500C, MnO2 is reduced to Mn.
MnO2 + 2C  Mn + 2CO
Ca3(OH)2  CaO + P2O5
CaO + SiO2  CaSiO3
2P2O5 + 10C  P4 + 10CO
5. Collection of Cast Iron: Metal is cast into ingots or in the laddle for further refining like
steel making.
Wrought Iron
Minimum % of carbon, is 0.1 – 0.15% and other impurities like S, P, Mn, Si less than 0.3%.
Manufacturing Process
Cast iron takes in puddling furnace and melted by hot blast of air. The chemical reactions
which occur are
S + O2  SO2 ; 3S + 2Fe2O3  4Fe + 3SO2
3Si + 2Fe2O3  4Fe + 3SiO2
Mn + Fe2O3  2Fe + 3MnO
MnO + Fe2O3  MnSiO3 (slag)
3C + Fe2O3  2Fe + 3CO
4P + 5O2  2P2O5; Fe2O3 + P2O5  2FePO4 (slag)
The impurities are removed from ion, the melting point of the metal rises and it becomes a
semi solid mass. Metal taken out from the furnace in the form of balls with the help of the
rabbles. The balls are then beaten under hammer to separate out the slag. The product thus
formed is thus called wrought iron.

13. 5.5 Steel
Manufacture from CI (Cast Iron)
Acid Besimer: This process is carried out when percentage of P is very low. The lining of the
furnace is made of SiO2. The following reactions take place to lessen the impurities.
2Mn + O2  2MnO
Si + O2  SiO2
MnO + SiO2  MnSiO3
S + O2  SO2
4Fe + 3O2 

 
 air
hot
2Fe2O3
Fe2O3 + 3C  2Fe + 3CO
2C + O2  2CO 
When the blue flame of CO drops out it complete oxidation of carbon.
All the reactions are exothermic. After the complete of the reaction calculated amount of
speigeleisen (an alloy of Fe, Mn, C) is added to the molten mass. After that again air blast is
continued for two minutes to engage the thorough mixing of the speigel. The function of
speigcleisen is to revert back ferrous from Fe state to reduce also of Fe, C, Mn.
FeO + Mn  MnO + Fe
FeO + C  Fe + CO
It acts as the deoxidiser to remove oxygen inclusion which in the metals the excess of are
elements dissolve in the molten Fe and thus supplies are requisite amount of carbon to iron
to produce steel of desired quality. Mn serves to make the steel harder and to increase its
tensile strength. The converter is then tilted and molten steel cast into moulds, or taken in
laddle for further processing.
Basic Besemer Process
The lining of the converter is of basic materials like CaO, MgO etc. Mn, Si of CI is first
oxidised. S from SO2, C, P are then oxidised to form CO.
2Mn + O2  MnO; MnO + SiO2  MnSiO3 (slag)
Si + O2  SiO2
S + O2  SO2
2C + O2  2CO
4P + 5O2  2P2O5
4CaO + P2O5 
slag
as
hom
T
2
4
3 ]
CaO
.
)
PO
(
Ca
[
Spiegeleisen is added to the molten Fe when it is converted and steel.

14. Open Hearth Process
Open hearth process is the mdern process for the manufacture of the high grade steel.
i) The impurities present in the C.I. are mainly oxidised by the addition of haematite ores
and the rest are oxidised by O2 of air.
ii) The percentage of C, Si is lowered down by the addition of scrap Fe.
iii) Heat generated by burning of mixture of produce gas air is used to preheat the fuel gas
and air.
This regenerative system causes an economic fuel consumption and maintains high
temperature (1800C) in the furnace.
Reactions taking place in the hearth
Mn, Si, P, S and carbon are oxiidsed by haematite (Fe2O3) to form their respective oxides.
The reactions occuring are as follows.
2Fe2O3 + 3Si  4Fe + 3SiO2
Fe2O3 + 3Mn  2Fe + 3MnO
2Fe2O3 + 3S  4Fe + 3SO2
Fe2O3 + 3e  2Fe + 3CO
5Fe2O3 + 6P  10 Fe + 3P2O5
MnO + SiO2  MnSiO3
CaO + SiO2  CaSiO3
3CaO + P2O5  Ca3(PO4)2
3MgO + P2O5  Mg3(PO4)2 (Slag mixture)
C, P are also oxidised by air to forms carbon monoxide and phosphorus pentoxide.
2C + O2  2CO
4P + 5O2  2P2O5
After the removal of impurities slag is separated, requisite amount of spiegeleisen is added
to the molten mass to obtain desired quality of steel by deoxidation and recarburisation.
FeSi and Al are also sometiems added for removal of O2 to make killed steel.
Duplex Process
This is actually a combination of acid besemer process and open hearth process. Si, Mn, S,
C (partially) are oxidised and removed or slag or volatite oxides. This process is applied in
TISCO.

15. Varieties of Steel
Carbon steel can be divided into the following groups.
i) Low carbon (mild steel) 0.15 - 0.3%
ii) Medium carbon steel 0.3 - 0.6%
iii) High carbon steel 0.6 - 0.8%
iv) Tool steel 0.8 - 1.4%
Alloy Steels
Nickel Steel (2 - 5%) Ni Very hard, tough, resistant
to corrosion
For making shafts,
gears, etc.
Chrome
steel
(13 - 14%) Cr,
0.7% Ni, 0.3% C
Resistant to corrosion For making house hold
materials.
Manganese
steel
9 - 14%Mn Very hard, resistant to ware For making helmets
Inver 30 - 36% Ni 0.3%
C
Coefficient of expansion is
very low
Measuring instruments
Alnico 20% Ni, 12% Al,
5% Co
High magnetic property For making strong
magnets.
Durairon 16% Si Resistant to acids Vessels for keeping
HCl, H2SO4 etc.
6. Extraction of Copper
6.1 Important Ores of Copper
i) Copper glance (chalcocite) Cu2S
ii) Copper pyrites (Chalopyrites) CuFeS2
iii) Malchite Cu(OH)2 CuCO3
iv) Cuprite or Ruby copper Cu2O
v) Azurite Cu(OH)22CuCO3
6.2 Metallurgy of Copper
Copper is extracted mainly from copper pyrites. The various steps involved are

16. Copper Pyrites
(CuFeS2)
Crushed and Sieved
Concentration by froth floatation
Powder ore + water + pine oil + air  sulphide ore in the froth
Rosting in reverberatory furnace in presence of air
S + O2  SO2; 2As + 3O2  2As2O3
2CuFeS2 + O2  Cu2S + 2FeS + SO2
Sand + Coke
Smelting in blast furnace in presence of air
2FeS + 3O2  2FeO + 2SO2; FeO + SiO2  FeSiO3 (slag)
Slag
Cu2O + FeS
(Matte)
Bassemerisation in bassemer converter in presence of air
2FeS + 3O2  2FeO + 2SO2; FeO + SiO2  FeSiO3
2Cu2S + 3O2  2Cu2O + 2SO2
2Cu2O + Cu2S
reduction
Auto


 
 6Cu + SO2
Blister copper (98% Cu + 2% impurities
*Electrolytic refining
Anode–impure copper plates
Cathode-pure copper plates
Electrolyte -CuSO4 + H2SO4
Pure copper at cathode (99.9% pure)
Chalcocite: Cu2S
Chalcopyritis: Cu2S Fe2S3
Cuprite Cu2O
Malachite CuCO3.Cu(OH)2
Azurite [2CuCO3.Cu(OH)2'

17. Extraction of metallic Cu
1. Concentration of the ore by oil floation process: Copper pyritis contains only (2-3)%
of copper. The rest of the ore contains iron or sulphide, silica, silicious materials,
sulphur, arsenic etc. as impurities. Froth flotation by Xanthate and pine oil. The froth is
collected and dried when concentrated ore is obtained which contains 25-30% of Cu.
2. Roasting
Cu2S.Fe2S3 + O2  Cu2S + 2FeS + SO2
Cu2S.Fe2S3 + 4O2  Cu2S + 2FeO + 3SO2
2Cu2S + 3O2  2Cu2O + 2SO2
Cu2O + FeS  Cu2S + FeO
3. Smelting of the roasted are in blast furnace: material required
1. Roasted ore
2. Lime stone
3. Coke (used as fuel)
4. Silica (used as flux)
5. Lime stone (used to remove excess silica)
Reactions occurring one as follows
2FeS + 3O2  2FeO + 2SO2
Cu2O + FeS  Cu2S + FeO
FeO + SiO2  FeSiO3 (removed as slag)
CaO + SiO2  CaSiO3 (removal as slag)
4. Self reduction in Bessemer Converter
Reactions involved are,
FeS + 3O2  FeO + SO2
FeO + SiO2  FeSiO3 (slag)
2Cu2S + 3O2  2Cu + SO2
Cu2S + 2O2  Cu2SO4
1/3 rd of Cu2S goes in Cu2SO4. Formation of 2/3 rd of Cu2S is oxidised while the blast of
hot air is stopped CuSO4 are reduced by the rest of cuprous sulphide to produce metallic
copper with the evolution of SO2
CuS + 2Cu2O  6Cu + SO2
Cu2SO4 + Cu2S  4Cu + 2SO2
Thus metallic copper is produced at the bottom of the furnace and collected as ingots.
This is blister Cu names so, due to the evolution of SO2- from the surface of metal.

18. 5. Refining
Electro refining
Anode: Impure copper obtained above
Cathode: Pure copper
Electrolyte: 15% CuSO4 solution + 5% H2SO4
Reactions coming are as follows
CuSO4 Cu+2
+ SO4
–2
At anode: Cu – 2e  Cu+2
At cathode: Cu+2
+ 2e  Cu
7. Extraction of Silver
7.1 Important Ores of Silver
i) Argentite or silver glance, Ag2S
ii) Horn Silver AgCl
iii) Pyargyrite (Ruby Silve), g2S, Sb2S3
7.2 Metallurgy of silver
Silver is mainly extracted from argentite (Ag2S) by Cyanide Process
Silver Ore (Argentite)
Concentration by froth floatation
Powder ore + water + pine oil + air  sulphide ore in the froth
CYANIDATION
Concentrated ore + NaCN solution (0.4 – 0.6%) + Air
Ag2S + 4NaCN 2NaAg(CN)2 + Na2S
4Na2S + 5O2 + 2H2O  2Na2SO4 + 4NaOH + 2S
Filtrate
Precipitation of silver with zinc
2NaAg(CN)2 + Zn 
ppt.
Black
Ag
2 + Na2Zn(CN)4
Black ppt. of Ag + KNO3 

 
fuse compact mass silver metal
Electrolytic refining
Anode–impure silver plates
Cathode-pure silver plates
Electrolyte -AgNO3 solution + HNO3
Pure silver at cathode

19. 8. Extraction of Tin
Ores:
Cassiterite (SnO2)
Extraction
1. Concentration: Crushed ore is water washed by a stream of water.
2. Roasting: S, As presentation in one ore are voltatlised away in the form of their oxides
in a revolving furnance.
3. Washing: It is then washed with hot water and mainly FeSO4 is present at this stage.
4. Electromagnetic separation: From the hopper the dry ore is supplied and from the belt
the FeSO4 is seperated by magnetic field. It contains 75%. SnO2 (black tin)
5. Carbon reduction:
SnO2 + C  Sn + 2Ca
Temperature 1200 – 1300C
Furnace: Reverberating furnace.
The molten tin is collected as 99% pure Sn. The upper layer of the slag contains 10-20%
Sn. This is melted with coke.
SnSiO3 + CaO + C  Sn + CaSiO3 + CO
6. Refining: This is carried out by sweating process. Sn metls leaving behind Fe, CuO, N.
Tin thus obtained is 99.5% pure.
Recovery of Sn from scrap:
The scrap tin plates, free from dirts are reacted by Cl2 to SnCl4. SnCl4 being liquid is
voltalised away and is condensed.
SnCl4 + 2H2O  SnO2 + 4HCl
SnO2 + 2C  Sn + 2CO
9. Extraction of Lead
Ores
Galena PbS
Anglesite PbSO4
Cerussite PbCO3
Lanerkite PbO, PbSO4
Croeoisite PbCrO4

20. Extraction
Galena is the commercially and economically viable ore. Steps can be shown by the
following flow chart diagram.
Ore Concentrated
ore
PbO + PbSO4 Lead (Pb)
Concentrations
by
The reaction at the that furnace as a follows
PbO + C  Pb + CO
PbO + CO  Pb + CO2
PbS + 2PbO  3Pb + SO2
PbS + PbSO4  2Pb + 2SO2
CaO + SiO2  CaSiO3 (Slag)
Fe2O3 + CO  2FeO + CO2
FeO + SiO2  FeSiO3 (slag)
Purification
Lead thus obtained contains Cu, Sb, Sn, As, Ag, Au etc., which make lead hard. In
reverberatory furnance, in presence of air impurities are oxidised and form same on the
surface of molten lead. The seem is removed after some internal until lead becomes soft.
10. Extraction of Magnesium
Magnesium from sea-water is obtained by the Dow's process. It consists of electrolysis of
molten magnesium chloride using an iron cathode and a graphite anode. Following are the
steps that involved during the process.
a) Mg+2
is precipitated as magnesium hydroxide by the addition of slaked lime, Ca(OH)2 to
the sea water.
Mg2+
+ Ca(OH)2  Mg(OH)2 + Ca2+
b) Magnesium hydroxide on treatment with hydrochloric acid is converted to chloride which
is crystallised as MgCl2.6H2O
Mg(OH)2 + 2HCl  MgCl2 + 2H2O
c) Now for electrolysis, magnesium chloride is fused as follows:
On passing a current of dry HCl gas it get partially dehydrated and the chloride thus
obtained is added to a molten mix. of sodium chloride and calcium chloride (temp. range
973 - 1023 K).Under this condition MgCl2 melt with the loss of water.
If magnesium chloride hydrate is heated strongly, it hydrolyses to yield magnesia
(magnesium oxide ) which is a refractory.
MgCl2.6 H2O  MgO + 2HCl + 5H2O

21. d) Molten mixture of MgCl2 , NaCl and CaCl2 is electrolysed. Magnesium is formed at the
cathode and chlorine is evolved at the anode. The chlorine is used to make HCl acid
which in turn is required for making magnesium chloride.
Cathode : Mg2+
+ 2e-
 Mg
Anode : 2Cl-
 Cl2 + 2e-
Illustration 4: NaCl is added during electrolysis of fused anhydrous MgCl2. Why?
Solution: NaCl is added as to lower the fusion temperature of MgCl2 and to make
the mixture as good conductor of electricity.
11. Some Other Important Compounds
1. MgCO3 Magnesite 2. MgCO3CaCO3 Dolomite
3. MgSO47H2O Epsomsalt 4. KClMgCl26H2O Carnallite
5. MgAl2O4 Spinal 6. H2MgSiO3 Talc
7.
Ca2Mg5Si8O22(
OH)2
Asbestos 8. KAlSi3O8 Feldspar
9. Cu(OH)2CuCO3 Malachite 10.
Cu(OH)22CuC
O3
Azurite
11. PbS Galena 12. Fe3O4 Magnetite
13. 3Fe2O33H2O Cimonite 14. AgNO3 Lunar Caustic
15. ZnSO47H2O White Vitriol 16. SnCl25H2O Butter or Iron
17. CaO Quick lime 18. Na2SO410H2O Glauber’s salt
19. Pb3O4 Red lead 20.
Pb(OH)22PbCO
3
White lead
21. Na2CO3 Soda ash 22. NaOH Caustic Soda
23. KOH
Caustic
potash
24. Ca(OH)2 Slaked lime
25. CaSO42H2O Gypsum 26. (CaSO4)2H2O Plaster of Paris
27. FeSO47H2O Green Vitriol 28. Hg2Cl2 Calomel
29. HgCl2
Carrosive
Sublimute
30. PbSO4 Anglesite
31. PbO Cittarge 32. ZnO Philosopher’s waal
33. HgS Cinnabar 34. BaSO4 Baryte or heavy spar
35. ZnS Zinc blende

22. 12. Some important Alloy
Sl. No. Name Composition
1. Stainless Steel Fe, Cr, Ni
2. Invar Fe, Ni
3. Alnico Fe, Al, Ni, Co
4. Brass Cu, Zn
5. Bronze Cu, Zn, Sn
6. Gun Metal Cu, Sn
7. Bell Metal Cu, Sn
8. German Silver Cu, Zn, Ni
13. Solution to Exercises
Exercise 1: Solvent extraction is the latest separation technique and has become
popular because of its elegance, simplicity and speed. The method is
based on preferential solubility principles.
Solvent or liquid-liquid extraction is based on the principle that a solute
can distribute itself in a certain ratio between two immiscible solvents, one
of which is usually water and the other an organic solvent such as
benzene, carbon tetrachloride or chloroform. In certain cases, the solute
can be more or less completely transferred into the organic phase. The
technique can be used for purpose of preparation, purification,
enrichment, separation and analysis.
Exercise 2: Both cupellation and poling are used for refining of metals, cupellation is
contain impurities of other metals with traces of lead are removed from
silver by heating impure silver with a blast of air in a cupel (an oval
shaped pan made up of bone ash) in which lead is oxidised to lead oxide
(PbO) which being volatile escapes leaving behind pure silver.
Poling is used for refining of such metals which contain impurities of its
own oxide. In this process, the molten impure metal is stored with green
wooden poles. At the high temperature of the molten metal, wood
liberates methane which reduces the oxide of the metal to free metal.
3Cu2O + CH4  6Cu + 2H2O + CO
Exercise 3: Certain oxides are not satisfactorily reduced by carbon. In such cases
aluminium is used as a reducing agent. A mixture of metallic oxide and
aluminium powder is ignited in a closed crucible by means of lighted
magnesium ribbon. Metals like chromium, manganese etc. are extracted
by thermite process as illustrated below.

23. Cr2O3 + 2Al  Al2O3 + 2Cr
3Mn3O4  4Al2O3 + 9Mn
The reaction is highly exothermic and the heat produced is sufficient to
melt the metal.
Exercise 4: i) Zone refining (Fractional crystallization) This method is employed
for preparing extremely pure metals. This method is based upon the
principle that when a molten solution of the impure metal is allowed to
cool, the pure metal crystilises out while the impurities remain in the
melt.
ii) Electro-refining: In this method, the impure metal is converted into a
block which forms the anode while cathode is a rod or plate of pure
metal. These electrodes are suspended in an electrolyte which is the
solution of a soluble salt of the metal usually a double salt of the
metal. When electric current is passed, metal ions from the electrolyte
are deposited at the cathode in the form of pure metal while an
equivalent amount of metal dissolves from the anode and goes into
the electrolyte solution as metal ion. The soluble impurities
present in the crude metal anode go into the solution while the
insoluble impurities settle down below the anode as anode mud.
iii) Van-Arkel Method: In this method, the metal is converted into it
volatile unstable compound such as iodide leaving behind the
impurities. The unstable compound thus formed is decomposed to get
the pure metal.
Ti(s) + 2I2(s) + 
 
 K
540
TiI4(g)
K
1700
)
s
(
Ti

 
 Ti + 2I2(g)

24. 14. Solved Problems
14.1 Subjective
Problem 1: Complete the following reactions:
a) Al(OH)4
–
+ CO2  ? + ? + ?
b) Ag+
+ Na2S2O3  ? + ?
c) 
4
MnO + H2S 
 
? + ?
Solution: a) O
H
CO
)
OH
(
Al
2
CO
)
OH
(
Al
2 2
2
3
3
2
4 



 

b) Ag+
+ 2Na2S2O3 
 Na3[Ag(S2O3)2] + Na+
c) 
4
MnO + H2S 
 Mn2+
+ SO2 + 2OH–
Problem 2: A sulfide ore (A) on roasting leaves a residue (B). (B) on heating with chlorine
gives (C), soluble in water, addition of excess potassium iodide to a solution of
(C) gives a solution (D). A brown precipitate (E)is formed when a solution of
ammonium sulfate is added to an alkaline solution of (D). Identify (A) to (E).
Solution: HgS 

 
roasting
HgO 
 
 2
Cl
HgCl2 



 
 
KI
of
excess
K2HgI4
(A) (B) (C) (D)
alkaline (NH4)SO4
HgOHg(NH2)I
(Brown ppt)
(E)
Problem 3: Write the balanced chemical equations for the following
a) Pb3O4 is treated with nitric acid
b) Zinc oxide is treated with excess of sodium hydroxide solution
c) Dilute nitric acid is slowly reacted with metallic tin
d) Gold is dissolved in aqua regia
e) Iron reacts with cold dilute nitric acid
f) Sodium thiosulphate is added slowly to silver nitrate
g) Heating of ZnCl22H2O
Solution: a) Pb3O4 is a mixed oxide, 2PbO, PbO2, with nitric acid PbO is converted to
Pb(NO3)2 while PbO2 remains as such
Pb3O4 + 2HNO3  PbO2 + Pb(NO3)2 + H2O
b) ZnO is dissolved as Zincate ion
ZnO + 2NaOH  Na2ZnO2 + H2O
c) Tin reduced nitric acid (dilute) to ammonia
4Sn + 
3
NO + 10H+
 4Sn2+
+ 
4
NH + 3H2O
d) Gold dissolves in aqua regia as HAuCl4
Au + 4HCl + 3HNO3  HAuCl4 + 3NO2 + 3H2O

25. e) 4Fe + 10HNO3  4Fe (NO3)2 + NH4NO3 + 3H2O
f) White precipitate changes to yellow, brown and finally becomes black
)
white
(
3
2
2
2
3
2 O
S
Ag
Ag
O
S 

 

4
2
)
Black
(
2
2
3
2
2 SO
H
S
Ag
O
H
O
S
Ag 



g) ZnCl22H2O 
 
ZnCl(OH) + HCl + H2O
Problem 4: Complete and balance the following equations
a) Zn + Fe2(SO4)3  ? + ?
b) CuSO4 
 
heat
? + ?
c) Al + conc. H2SO4  ? + ? + ?
d) Al2O3 + C + N2 
 
heat
? + ?
e) Pb + O2 + H2O 
 ?
Solution: a) Zn + Fe2(SO4)3 
 ZnSO4 + 2FeSO4
b) CuSO4 
 
CuO +SO3
c) 2Al + conc. 6H2SO4  Al2(SO4)3 + 3SO2 + 6H2O
d) Al2O3 + 2C + N2 
 
2AlN + 3CO
e) 2Pb + O2 + 2H2O 
 2Pb (OH)2
Problem 5: In moist air copper corrodes to produce a green layer on the surface. Explain.
Solution: In presence of moist air a thin film of green basic copper carbonate is formed
on its surface and hence copper corrodes
2Cu + O2 + H2O + CO2 
green
2
3 )
OH
(
Cu
CuCO 
Problem 6: Why does AgNO3 produce a black stain on the skin.
Solution: In presence of organic matter (skin) and light, AgNO3 decomposes to
produces a black stain of metallic silver
2AgNO3  2Ag + 2NO2 + O2

26. 14.2 Objective
Problem 1: Which of the following oxides of nitrogen combines with Fe (II) ions to form a
dark brown complex?
(A) N2O (B) NO
(C) NO2 (D) N2O5
Solution: (B)
Problem 2: Of the following acids
I : hypo phosphorous acid II: hydroflouric acid
III: oxalic acid IV: glycine
(A) I, II are monobasic, III dibasic acid and IV amphoteric
(B) II monobasic, I, III dibasic acid, IV amphoteric
(C) I monobasic, II, III dibasic, IV amphoteric
(D) I, II, III dibasic, IV amphoteric
Solution: (A)
Problem 3: In the following statements, select the correct statement :
(A) N(CH3)3 has pyramidal structure
(B) N(SiH3)3 shows planar arrangement
(C) both correct
(D) none is correct
Solution: (C)
Problem 4: A solution of sodium in liquid ammonia is strongly reducing agent due to the
presence of
(A) Na atoms (B) Sodium hydride
(C) sodium amide (D) solvated electron
Solution: (D)
Problem 5: Amongst sodium halides NaF has the highest m.p. because it has
(A) highest oxidising power (B) lower polarity
(C) minimum ionic character (D) maximum ionic character
Solution: (D)
Problem 6: Molecular formula of Glauber's salt is
(A) MgSO4,7H2O (B) FeSO4,7H2O
(C) CuSO4,5H2O (D) Na2SO4, 10H2O
Solution: (D)
Problem 7: A solution of Na2SO4 in water is electrolysed using inert electrodes. The
products at the cathode and anode are respectively
(A) H2,O2 (B) O2,H2
(C) O2,Na (D) O2,SO2
Solution: (A)

27. Problem 8: Which of the following does not give flame test?
(A) Na (B) Sr
(C) K (D) Zn
Solution: (D)
Problem 9: In the electrolysis of alumina, cryolite is added to alumina to
(A) Lower the m.p. of alumina (B) Increase the electrical conductivity
(C) Minimise the anode effect (D) remove impurities from alumina
Solution: (B)
Problem 10: which of the collowing statements regarding anhydrous AlCl3 is correct?
(A) It exists as AlCl3 molecule
(B) it is not easily hydrolysed
(C) it sublimes at 100°C under vacuum
(D) it is a Lewis base
Solution: (C)
Problem 11: In the Alumino thermit process Al acts as
(A) an oxidising agent (B) a flux
(C) a reucing agent (D) a solder
Solution: (C)
Problem 12: Which of the following statements is not correct?
(A) Al forms only ionic compounds
(B) Al utensils are used commonly
(C) Al is one of the best conductor of electricity
(D) Al is a light metal of high tensile strength
Solution: (A)
Problem 13: Lead pencil contains
(A) Pb (B) FeS
(C) Graphite (D) PbS
Solution: (C)
Problem 14: When lead storage battery is discharged
(A) Lead is formed (B) H2SO4 is consumed
(C) SO3 is evolved (D) PbO2 is formed
Solution: (B)
Problem 15: Red lead is
(A) PbO2 (B) PbO
(C) Pb3O4 (D) PbO2
Solution: (C)

28. Problem 16: Pewter is
(A) 20% Pb, 80% Sn (B) 50% Pb, 50% Sn
(C) 83% Pb, 3% Sn, 14% Sb (D) 60% Pb, 30% Sb, 10% Sn
Solution: (A)
Problem 17: Butter of tin is
(A) (NH4)2SnCl6 (B) SnCl2 + Sn(OH)2
(C) SnCl4, 5H2O (D) H2SnCl4
Solution: (C)
Problem 18: Cyanide process is applicable for the extraction of
(A) Ag (B) Ca
(C) Fe (D) Mg
Solution: (A)
Problem 19: A cupric salt on being heated with metallic Cu and conc. HCl the colour of the
solution is discharged due the formation of a
(A) CuCl2 (B) Cu2Cl2
(C) H[CuCl2] (D) H[CuCl3]
Solution: (C)
Problem 20: From brass, Cu may be separated by :
(A) heating brass with conc NaOH soln.
(B) treatment with dilute HNO3
(C) Fractional crystallisation
(D) treatment with dilH2C2O4
Solution: (A)
Problem 21: AgCl on fusion with Na2CO3 form
(A) Ag2CO3 (B) Ag2O
(C) Ag (D) Ag2C2
Solution: (C)
Problem 22: AgCl precipitate dissolves in NH4OH due to the formation of
(A) AgCl, 2NH3 (B) [Ag(NH3)2]Cl
(C) [Ag(NH3)4]Cl, (D) [Ag(NH3)2]OH
Solution: (D)
Problem 23: When H2S passed through an ammoniacal salt solution (X), a white precipitate
is obtained. The (X) can be
(A) Fe(OH)3 (B) Zn(OH)2
(C) Cu(OH)2 (D) Mg(OH)2
Solution: (B)

29. Problem 24: Which of the following is soluble in ecess of NaOH?
(A) Fe(OH)3 (B) Zn(OH)2
(C) Cu(OH)2 (D) Mg(OH)2
Solution: (B)
Problem 25: Which of the following dissolves in hot conc. solution of NaOH
(A) Zn (B) Fe
(C) Ag (D) Cu
Solution: (A)
Problem 26: Normal zinc carbonate is prepared by treating an aqueous solution of ZnCl2
with
(A) Na2CO3 (B) NaHCO3
(C) by passing CO2 (D) K2CO3
Solution: (B)
Problem 27: Which of the following is the weakest base
(A) NaOH (B) KOH
(C) Ca(OH)2 (D) Zn(OH)2
Solution: (D)
Problem 28: In the metallurgy of iron, when limestone is added to the blast furnace, the Ca++
ion ends up in
(A) slag (B) gangue
(C) metallic calcium (D) Calcium carbonate
Solution: (A)
Problem 29: The rusting of iron is catalysed by which of the following
(A) Zn (B) Fe
(C) O2 (D) H+
Solution: (B)
Problem 30: Iron is rendered passive by treatment with concentrated
(A) H2SO4 (B) H3PO4
(C) HCl (D) HNO3
Solution: (D)

30. 15. Assignments (Subjective Problems)
LEVEL – I
1. AgNO3 is treated with Na2S2O3 solution.
2. AgNO3 is heated at 212°C and red heated
3. Lead dioxide is treated with H2C2O4 in HNO3 medium.
4. Ammonium dichromate is heated
5. ZnS is heated in air
6. ZnO is treated with HCl and NaOH separately.
7. ZnSO4.7H2O is heated
8. When a Zn rod is hung in a solution of led nitrate or acetate a mass of arborescent
crystals (lead tree) slow deposits.
9. CuSO4.5H2O is heated.
10. FeSO4.7H2O (green vitriol) is heated.
11. Oxide (A) of white metal (B) when reacts with glucose produces metal (B) and an
organic acid (C) of empirical formula C6H12O7 Halide (D) of (B) when reacts solution
washing soda produces two gas (E), (F). (F) being a strong oxidant produces a
sulphate (G) with the sulphide of metal (B).
12. The gas liberated on heating a mixture of two salts with NaOH gives a reddish brown
precipitate with an alkaline solution of K2HgI4. The aqueous solution of the mixture on
treatment with BaCl2 gives a white precipitate which is sparingly soluble in conc. HCl.
On heating the mixture with K2Cr2O7 and conc. H2SO4, red vapours (A) are
produced. The aqueous solution of the mixture gives a deep blue coloration (B) with
potassium ferricyanide solution. Identify the radicals in the given mixture and write
the balanced equations for the formation of (A) and (B).
13. a) A crystalline inorganic compound (A) when it came, in contact with skin leaves a
black stain (A) is freely soluble in water and where to this solution some NaCl is
added, a white ppt appears is insoluble inHNO3 but soluble in NH4OH. When
hydrogen sulphide is formed through a solution of (A), a black ppt. appears.
When potassium chromate is added to the solution of (A), a brick red ppt. results.
To another portion of solution (A), mixed with FeSO4 in a test tube, concentrated
H2SO4 is added through the sides of the test tube, a brown ring results. Identify
the compound and give equations for the various reactions involved.
b) An inorganic compound, dark red in anhydrous state, it absorbs moisture to
become yellow. On heating it sublines to form alimesic state in vapour phase. It
acts on oxidant for SnCl2, liberates I2 from KI and converts H2S to S. Its aqueous
solution is acidic. On heating aquous solution with K4[Fe(CN)6], a characteristic

31. blue colour is obtained. What is the compound and give all the reactions
involved?
14. A solution of salt (A) yields white ppt. with dil. HCl. The ppt. is soluble in hot (A) when
mixed with K2CrO4 solution a yellow compound known as ‘Lemon chrome’ widely
used on pigment fumes of (B) with conc.H2SO4; The brown fumes on dissolution in
water gives a colourless solution (C) acidic in nature Find A, B, C
15. Heavy metal compound (A) on heating produceds a gas (B) of which if its central
element attain +2 oxidation state gives a paramagnetic oxide (C). (A) on treatment
when perchromic acid produces yellow crystalline ppt (D). (B) on reaction with water
produces two acids (E), (F), (F) on heating gives (B). Find (A) to (F)

32. LEVEL – II
1. Ferrous sulphate is treated with K3Fe(CN)6 solution
2. Ferric chloride is treated with K4 ]
)
CN
(
Fe
[ 6
II
.
3. FeCl3 is treated with KCNS and F–
is added subsequently.
4. Fe2O3 is treated with HCl and NaOH separately.
5. Na2H2PO4 

 
 C
150
o



 
 C
300
o
 238° – 300°C
6. Identify the complexes which are expected to be coloured. Explain:
a) i) [Ti(NO3)4] ii) [Cu(NCCH3)4]+ 
4
BF
iii) [Cr(NH3)6]3+
3Cl iv) K3[VF6]
b) Complete and balance the following reactions:
i) [MnO4]2–
+ H+
 ------ + [MnO4]–
+ H2O
ii) Ca5(PO4)3F + H2SO4 + H2O 

 
heat ----------- + 5CaSO4.2H2O + -----------
iii) SO2(aq) + 2
7
CrO + 2H+
 --------- + --------- + ----------
iv) Sn + 2KOH + 4H2O  -------- + ----------
c) Give reasons for the following
Although aluminium is above hydrogen in the electrochemical series, it is stable
in air and water.
7. a) Write balanced equations for the following:
i) Phosphorus is treated with concentrated nitric acid
ii) Oxidation of hydrogen peroxide with potassium permanganate in acidic
medium.
iii) Reaction of zinc with dilute nitric acid.
b) Element A burns in nitrogen to given an ionic compound B. compound B reacts
with water to give C and D. A solution of C becomes milky on bubbling carbon
dioxide. Identify A,B,C and D.
8. a) Thionyl chloride can be synthesized by chlorinating SO2 using PCl5./ Thionyl
chloride is used to prepare anhydrouys ferric chloride starting from its
hexahydrated salt. Alternatively, the anhydrous ferric chloride can also by
prepared from its hexahydrated salt by treating with 2,2-dimethoxypropane.
Discuss all this using balanced chemical equations.
b) Reaction of phosphoric acid with Ca5(PO4)3F yields a fertilizer "triple
superphosphate". Represent the same through balanced chemical equation.
9. A metal (A) with melting point 232C when reacts with acid dil. HNO3 produces (B)
and a gas (C) (C) is brown coloured gas. (C) on reaction with water produces two
acids (D), (E), (B) when on heating decomposes to its oxide (F), white colour
compound. Chloride of (A) will produces grey ppt. (G) with mercurous chloride.

33. 10. White lustrous metal (A) on reaction dil. HNO3 produces a gas (B) helps in burning
an which is paramagnetic and (C) (C) with iodine produces (D) a white precipitate.
(C) solids or an laypr solutionproduces (E). (E) on hydrolysis gives black ppt (F).
11. A pale yellow solid (A) when reacts with excess ammonia produces complex (B)
whose structure of the co-ordination sphere is linear. (A) while reacts with (C) gives a
white ppt (D) but in excess of (C) gives soluble complex (E). Bromide of the metal
has the effect on photographic film. Find A to E.
12. Halogen (A) when reacts with a gas (B) gives (C) of brown collur (C) on reaction with
KI produces violet vapour (D). (A) when is in +5 oxidation state on reaction in acid
medium with KI produces (D). (B) produces yellow colloidal precipitation (E) with
H2S.
13. A colourless gas (A) when reacts with ammonical cuprous chloride produces an
addition compound (B). (A) when reacts alkali produces a fatty acid salt (C). If (B) is
heated gas (A) comes out and with halogen (D) produces a poisonous compound (E)
and with S vapour produces a compound (F). Find A to F.
14. An element of group V on reaction with concentrated H2SO4 gives an aicd (B) and an
oxide (C). (C) on reaction with acidified dichromate produces the acid (D). (D) is
having very strong affinity to water. (A) with metal (E) produces as hydrolysis a gas
(F) of odoour of decaying fish. Find A to F.
15. Metal hydroxide (A) on reaction with halogen (B) produces a insecticide (C). (C) on
reaction with a hydride of a non-metal (D) produces same (A). Hydride (D) reduces
CuSO4 and produces (E) a black ppt. chloride of Cu(F) absorbs (D). Find A to F.

34. LEVEL – III
1. Compound (A) is greenish crystalline salt, which gave the following results. (1)
Addition of BaCl2 solution to the solution of (A) resultss in the formation of a white
ppt. (B), which is insoluble in dil. HCl.
On heating (A), water vapours and two oxides of sulphur, (C) and (D) liberated
leaving a red brown residue (B).
(E) dissolves in warm conc. HCl to give a yellow solution (F)
With H2S, the solution (F) yields a pale yellow ppt (A) which when filtered, leaves a
greenish filtrate (H).
2. The gas liberated on heating a mixture of two salts with NaOH gives a raddish brown
precipitate with an alkaline solution of K2 HgI4. The aqueous solution of the mixture
on treatment with BaCl2 gives a white precipitate which is sparingly soluble in
concentrated HCl. On heating the mixture with K2Cr2O7 and conc. H2SO4, red
vapours (A) are produced. The aqueous solution of the mixture gives a deep blue
colouration (B) with K3[Fe(CN)6] solution. Identify the raidcals in the given mixture
and write the balanced equations for the formation of (A) and (B).
3. i) A black mineral (A) to treatment with dilute NaCN solution in presence of air
gives a clear solution of (B) and (C).
ii) The solution of (B) on reaction with Zn gives precipitate of a metal (D).
iii) D is dissolved in dil. HNO3 and the resulting solution gives a white ppt. (E) with
dil. HCl.
iv) (E) on fusion with Na2CO3 gives (D).
v) (E) dissolves in aqueous solution of NH3 giving a colourless solution of (F)
vi) Identify (A) to (F)
4. An inorganic compound (A) shows the following reaction.
i) It is white solid and exists as dimer; gives fumes of (B) with wet air.
ii) It sublines in 180C and form monomer if heated to 400C.
iii) Its aqueous solution turns blue litmus to red.
iv) Addition of NH4OH and NaOH seperately to a solution of (A) gives white ppt.
which ihowever soluble in excess of NaOH.
5. A white crystalline solid obtained by the intersection of NH4F and NaNO3 with
aluminium fluoride of melting point 1000C. Product (A) when heated with lime
produces a compound (B) which on hydrolysis gives (C) which with alizarin gives
lake type precipitate (D) in ammonical solution. Metal of (D) on reaction (E) which on
subsequent hydrolysis gives (C) again. Identify A to E.
6. i) A precipitate (B) is formed when a mineral (A) is boiled with Na2CO3 soluton.
ii) The precipitate is filtered and the filtrate contains two compounds (C) and (D).
The compound (C) is removed by crystallisation and when CO2 is paired through
the mother liquor left (D) changes to (O).
iii) The compound (C) an strong heating gives two compounds (D) and (E)
iv) (E) on heating with CO produces blue coloured substance (F)
Identify (A) to (F) and give chemical equation for the reactions at steps (i) to (iv)

35. 7. Potassium ferrocyanide is treated with H2O2 in acid media
8. Potassium ferricyanide is treated with H2O2 in alkaline media
9. 3
6
)
CN
(
Fe 
is treated with N2H4.
10. AlCl3 is heated at 70°C with NF3
11. Ferrous sulphate is treated with potassium dichromate
12. Ferric chloride is treated with NH4CNS
13. White metal having sp, gr. 10.5 on treatment with KCN produces complex salt (B).
(B) when reacts with another metal (C) produces (A). Nitrate of (A) when red heated
produces two gases (D), (F). (D) below –9C is diomesic colourless crystal. (A) with
HCl and a gas (E) produces its halide F. Find (A – F) write the reaction also.
14. A mineral (A) on fusion with Na2CO3 white ppt. (B) and a solution which on
concentration and costing gives a colourless gas (D) and a solid (E). With CO2 (E)
again forms compound (B). Compound C on treatment with hot conc. HCl followed
by hydrolysis gives (F). Compound (F) on strong heats gives (G) which an heating
chromic sulphate gives a green bead of chromic borate and SO3 gas. What are (A) to
(G). Explain reactions involved.
15. When Cu is heated with conc. H2SO4 a pungent gas (A) and a salt (B) is obtained.
Gas (A) dissolves in H2O to give an acid which is unstable and oxidised to a more
stable acid (C). The acid (C) reacts with BaCl2 solutioin to a give a white ppt.
insoluble in conc. HNO3. The gas (A) is a strong reducing agent. It reduces Br2, I2 to
HBr and HI respectively. (A) gives a white ppt of (D) on reaction with HgCl2. Soluton
FeCl3 is reduced to FeCl2 by (A). (A) converts HCl solution of FeCl2 into FeCl3. Find
(A to E).

36. 16. Assignments (Objective Problems)
LEVEL – I
1. Of the following reduction process, which one is carried out in blast furnace
(A) Fe2O3 + C  Fe (B) ZnO + C  Zn
(C) Ca3(PO4)2 + C  P (D) PbO + C  Pb
2. Following reaction is not involved in Thermite process:
(A) 3Mn3O4 + 8AI  9Mn + 4Al2O3 (B) Cr2O3 + 2AI  Al2O3 + 2Cr
(C) 2Fe + Al2O3  2Al + Fe2O3 (D) B2O3 + 2AI  2B + Al2O3
3. Consider the following steps: CuS 



 
 air
in
roast (A) )
B
(
air
without
roast 





 

Which is not the correct statement
(A) It is self - reduction
(B) it is involves disproportionation Cu2S  Cu + CuS
(C) A is a mixture of CuO and CuS and (B) is a mixture of Cu and SO2
(D) All are incorrect statements
4. Na2CrO4 and Fe2O3 are separate by:
(A) dissolving in conc. H2SO4 (B) dissolving in NH3
(C) dissolving in H2o (D) dissolving in dil. HCl
5. Match the reactions taking place in blast furnace with temperature range of
operations
Reactions Temperature
(A) : Fe2O3 + CO  CO2 + Fe (I) 1200°C
(B) :C + CO2  CO (II) 900°C
(C) : C + H2O  CO + H2 (III) 600°C
(D) :CaO + SIO2  CaSiO3 (IV) 1100°C
Choose the correct alternate:
A B C D
(A) IV III II I
(B) II IV III I
(C) I II IV III
(D) I II III IV
6. Match column (A) (process) with column (B) (electrolyte)
A (process) B (electrolyte)
I Downs cell (W) fused MgCl2
II Dow sea water process (X) fused (Al2O3 + Na3AlF6)
III Hall - Heroult (Y) fused KHF2
IV Moissan (Z) fused (40% NaCl + 60% CaCl2)
Choose the correct one
I II III IV I II III IV
(A) Z W X Y (B) X Y Z W
(C) W Z X Y (D) X Z W Y

37. 7. In the Pidgeon process, Mg is produced by
(A) electrolysis of fused MgCl2
(B) reducing calcine dolomite with ferrosilicon at high temperature under pressure
(C) both are correct
(D) none is correct
8. Which of the following is not an ore:
(A) malachite (B) calamine
(C) stellite (D) cerussite
9. On igniting Fe2O3 at 1400°C, the product obtained is:
(A) Fe2O3 melt (B) FeO
(C) Fe3O4 (D) metallic iron
10. Consider the following statements: Roasting is carried out to:
1. Convert sulphide to oxide and sulphate
2. Remove water of hydration
3. Melt the ore
4. Remove arsenic and sulphur impurities
Of these statements
(A) 1,2 and 3 are correct (B) 1 and 4 are correct
(C) 1,2 and 4 are correct (D) 2,3 and 4 are correct
11. Carbon cannot be used in the reduction of Al2O3 because:
(A) it is an expensive proposition
(B) the enthalpy of formation of CO2 is more than that of Al2O3
(C) pure carbon is not easily available
(D) the enthalpy of formation of Al2O3 is too high
12. Ag2S + NaCN  (A)
(A) + Zn  (B)
(B) is a metal. Hence (A) and (B) are
(A) Na2[Zn(CN04], Zn (B) Na[Ag(CN)2], Ag
(C) Na2[Ag(CN)4], Ag (D) Na3[Ag(CN)4], Ag
13. Refining of silver is done by
(A) liquation (B) poling
(C) cupellation (D) van Arkel method
14. Match the method of concentration of the ore in column I with the ore in column II
and select the correct alternate.
I II
X Magnetic separation A Ag2S
Y froth floation B FeCr2O4
Z Gravity separation C Al2(SiO3)3
X Y Z X Y Z
(A) A B C (B) B A C
(C) C A B (D) B C A
15. Which of the following does not contain Mg:
(A) magnetite (B) magnesite
(C) asbestos (D) carnallite

38. LEVEL - II
1. Ag2S + NaCN + Zn  Ag
This method of extraction of Ag by complex formation and then its displacement is
called
(A) Parke's method (B) McArthur-Forest method
(C) Serpeck method (D) Hall' method
2. In zone - refining method the molten zone
(A) consists of impurities only
(B) contains more impurity than the original metal
(C) contains the purified metal only
(D) moves to either side
3. Match List I with List II and select the correct answer using the codes gives below the
lists:
List - I List - II
A. van Arkel method 1. Manufacture of caustic soda
B. Solvay process 2. Purification of titanium
C. Cupellation 3. Manufacture of Na2CO3
D. Poling 4. Purification of copper
5. Refining of silver
Codes:
A B C D
(A) 2 1 3 4
(B) 4 3 2 5
(C) 2 3 5 4
(D) 5 1 3 4
4. Formation of metallic copper from the sulphide ore in the normal thermo-
metallurgical process essentially involves which one of the following reaction.
(A) CuS +
2
3
O2  CuO + SO2;
CuO + C  Cu + CO
(B) CuS +
2
3
O2  CuO + SO2;
2CuO + CuS  3Cu + SO2
(C) CuS + 2O2  CuSO4;
CuSO4 + CuS  CuSO4;
(D) CuS +
2
3
O2  CuO + SO2;
CuO + CO  Cu + CO2
5. Annealing of steel is the process of heating steel
(A) to a bright red hot and then cooling it slowly
(B) to a bright red hot and then cooling it suddenly
(C) to a temperature much below redness and cooling it slowly
(D) none

39. 6. Out of AgF, CaF2, BeF2, MgF2
(A) AgF and BeF2 are soluble, and CaF2 and MgF2 are insoluble in water
(B) AgF is soluble, others insoluble
(C) CaF2, BeF2, MgF2 soluble, AgF insoluble
7. Which is used for fixing atmospheric nitrogen
(A) CaCN2 (nitrolim) (B) Li3N
(C) Mg3N2 (D) all
8. BaC2 + N2 
 (A)
CaC2 + N2 
 (B)
(A) and (B) are
(A) BaCN2, CaCN2 (B) Ba(CN)2, Ca(CN)2
(C) Ba(CN)2, CaCN2 (D) none is correct
9. The common name, "cream of tartar" refers to:
(A) KHC4H4O6 (B) K(SbO)C4H4O6
(C) KNaC4H4O6 (D) Mg2(OH)2(C4H4O6)H2O
10. A basic refractory material among the following is :
(A) Al2O3 (B) SiO2
(C) Fe2O3 (D) CaO
11. Which of the following mixtures cannot be prepared
(A) NaHCO3 + Na2CO3 (B) Na2CO3 + NaOH
(C) NaHCO3 + NaOH (D) H2CO3 + NaHCO3
12. Na2[Be(OH)4] is formed when :
(A) BeO reacts with NaOH solution (B) Be reacts with NaOH solution
(C) both correct (D) none is correct
13. Which is used to treat acid indigestion:
(A) Al4C3 + H2O  CH  CH (B) CaC2 + H2O  CH  CH
(C) Mg4C3 + H2O  CH3C  CH (D) All true
14. Na+
and Ag+
differ in
(A) Na2CO3 is thermally stable while Ag2CO3 decompose into Ag, CO2 and O2
(B) Ag+
forms complexes, Na+
does not
(C) NaCl is water soluble, AgCl is insoluble
(D) NaCl and AgCl both give colour in flame when ignited
15. When Cl2 is passed into moist slaked like, compound formed is:
(A) CaO2Cl2 (B) CaO2Cl
(C) CaOCl2 (D) CaCl2O4

40. 17. Answers (Objective Problems)
LEVEL - I
1. A 2. C
3. B 4. A
5. B 6. A
7. B 8. C
9. D 10. C
11. D 12. B
13. A 14. B
15. A
LEVEL - II
1. B 2. B
3. C 4. B
5. A 6. A
7. A 8. C
9. B 10. D
11. C 12. C
13. C 14. A
15. C
6