Page 1
JEE Advanced Previous Year Questions
(2021-2023): General Principles and
Processes of Isolation of Metals
2023
Multiple Correct Type
JEE Advanced 2023 Paper 1 Online
Q1. The correct statement(s) related to processes involved in the extraction of metals is(are) :
A. Roasting of Malachite produces Cuprite.
B. Calcination of Calamine produces Zincite.
C. Copper pyrites is heated with silica in a reverberatory furnace to remove iron.
D. Impure silver is treated with aqueous ?????? in the presence of oxygen followed by reduction
with zinc metal.
Ans: (B,C,D)
(A) Roasting of malachite
CuCO
3
Cu(OH)
2
?
+O
2
CuO + H
2
O + CO
2
Roasting means that heating of substance in excess of oxygen. So cuprite Cu
2
O is not produced. Hence,
this statement is not correct.
(B) Calcination means heating in absence of air
ZnCO
3
Calamine
?
h?????? ZnO
Zincite
+ CO
2
? Statement is true.
(C)
CuFeS
2
+ O
2
?
h?????? Cu
2
S + FeO + SO
2
FeO + SiO
2
? FeSiO
2
? Statement is true.
(D)
Ag + KCN + O
2
+ 2H
2
O ? 4 K[Ag(CN)
2
] + 4KOH
2 K[Ag(CN)
2
] + Zn ? K
2
[Zn(N)
4
] + 2Ag
Silver is obtained by reaction with Zinc
So, the above statement is true.
Page 2
JEE Advanced Previous Year Questions
(2021-2023): General Principles and
Processes of Isolation of Metals
2023
Multiple Correct Type
JEE Advanced 2023 Paper 1 Online
Q1. The correct statement(s) related to processes involved in the extraction of metals is(are) :
A. Roasting of Malachite produces Cuprite.
B. Calcination of Calamine produces Zincite.
C. Copper pyrites is heated with silica in a reverberatory furnace to remove iron.
D. Impure silver is treated with aqueous ?????? in the presence of oxygen followed by reduction
with zinc metal.
Ans: (B,C,D)
(A) Roasting of malachite
CuCO
3
Cu(OH)
2
?
+O
2
CuO + H
2
O + CO
2
Roasting means that heating of substance in excess of oxygen. So cuprite Cu
2
O is not produced. Hence,
this statement is not correct.
(B) Calcination means heating in absence of air
ZnCO
3
Calamine
?
h?????? ZnO
Zincite
+ CO
2
? Statement is true.
(C)
CuFeS
2
+ O
2
?
h?????? Cu
2
S + FeO + SO
2
FeO + SiO
2
? FeSiO
2
? Statement is true.
(D)
Ag + KCN + O
2
+ 2H
2
O ? 4 K[Ag(CN)
2
] + 4KOH
2 K[Ag(CN)
2
] + Zn ? K
2
[Zn(N)
4
] + 2Ag
Silver is obtained by reaction with Zinc
So, the above statement is true.
2022
JEE Advanced 2022 Paper 2 Online
Q1. The correct option(s) related to the extraction of iron from its ore in the blast furnace
operating in the temperature range ?????? - ???????? ?? is(are)
A. Limestone is used to remove silicate impurity.
B. Pig iron obtained from blast furnace contains about ?? % carbon.
C. Coke (C) converts ????
?? to ???? .
D. Exhaust gases consist of ????
?? and ???? .|
Ans: (A,B,C)
(A) Limestone is added to remove silica as impurity.
(B) Pig iron obtained from blast furnace contains 4% carbon and many other impurities (eg. S, P, Si, Mn)
in small amount.
(C) Coke (C) converts CO
2
in CO.
C + CO
2
? 2CO
(D) Exhaust gases consist of CO and CO
2
.
Hence, (?? , ?? , ?? ) are correct.
JEE Advanced 2022 Paper 1 Online
Q2. The electrochemical extraction of aluminum from bauxite ore involves
A. the reaction of ????
?? ?? ?? with coke (?? ) at a temperature > ???????? °
?? .
B. the neutralization of aluminate solution by passing ????
?? gas to precipitate hydrated alumina
(????
?? ?? ?? · ?? ?? ?? ?? ).
C. the dissolution of ????
?? ?? ?? in hot aqueous ???????? .
D. the electrolysis of ????
?? ?? ?? mixed with ????
?? ?????? ?? to give ???? and ????
?? .
Ans: (B,C,D)
(A) The reduction of Al
2
O
3
with coke (C) at a temperature > 2500
°
C is not carried out due to the
formation of carbides.
(B) It is correct as neutralisation of aluminate solution is done by passing CO
2
gas to precipitate hydrated
alumina.
(C) Reaction of powdered one is carried out with hot concentrated NaOH at 473 K - 523 K and 35 - 36
bar pressure.
(D) Electrolysis of Al
2
O
3
is done mixed with Na
3
AlF
6
to produce Al and CO
2
. It is a correct statement.
Page 3
JEE Advanced Previous Year Questions
(2021-2023): General Principles and
Processes of Isolation of Metals
2023
Multiple Correct Type
JEE Advanced 2023 Paper 1 Online
Q1. The correct statement(s) related to processes involved in the extraction of metals is(are) :
A. Roasting of Malachite produces Cuprite.
B. Calcination of Calamine produces Zincite.
C. Copper pyrites is heated with silica in a reverberatory furnace to remove iron.
D. Impure silver is treated with aqueous ?????? in the presence of oxygen followed by reduction
with zinc metal.
Ans: (B,C,D)
(A) Roasting of malachite
CuCO
3
Cu(OH)
2
?
+O
2
CuO + H
2
O + CO
2
Roasting means that heating of substance in excess of oxygen. So cuprite Cu
2
O is not produced. Hence,
this statement is not correct.
(B) Calcination means heating in absence of air
ZnCO
3
Calamine
?
h?????? ZnO
Zincite
+ CO
2
? Statement is true.
(C)
CuFeS
2
+ O
2
?
h?????? Cu
2
S + FeO + SO
2
FeO + SiO
2
? FeSiO
2
? Statement is true.
(D)
Ag + KCN + O
2
+ 2H
2
O ? 4 K[Ag(CN)
2
] + 4KOH
2 K[Ag(CN)
2
] + Zn ? K
2
[Zn(N)
4
] + 2Ag
Silver is obtained by reaction with Zinc
So, the above statement is true.
2022
JEE Advanced 2022 Paper 2 Online
Q1. The correct option(s) related to the extraction of iron from its ore in the blast furnace
operating in the temperature range ?????? - ???????? ?? is(are)
A. Limestone is used to remove silicate impurity.
B. Pig iron obtained from blast furnace contains about ?? % carbon.
C. Coke (C) converts ????
?? to ???? .
D. Exhaust gases consist of ????
?? and ???? .|
Ans: (A,B,C)
(A) Limestone is added to remove silica as impurity.
(B) Pig iron obtained from blast furnace contains 4% carbon and many other impurities (eg. S, P, Si, Mn)
in small amount.
(C) Coke (C) converts CO
2
in CO.
C + CO
2
? 2CO
(D) Exhaust gases consist of CO and CO
2
.
Hence, (?? , ?? , ?? ) are correct.
JEE Advanced 2022 Paper 1 Online
Q2. The electrochemical extraction of aluminum from bauxite ore involves
A. the reaction of ????
?? ?? ?? with coke (?? ) at a temperature > ???????? °
?? .
B. the neutralization of aluminate solution by passing ????
?? gas to precipitate hydrated alumina
(????
?? ?? ?? · ?? ?? ?? ?? ).
C. the dissolution of ????
?? ?? ?? in hot aqueous ???????? .
D. the electrolysis of ????
?? ?? ?? mixed with ????
?? ?????? ?? to give ???? and ????
?? .
Ans: (B,C,D)
(A) The reduction of Al
2
O
3
with coke (C) at a temperature > 2500
°
C is not carried out due to the
formation of carbides.
(B) It is correct as neutralisation of aluminate solution is done by passing CO
2
gas to precipitate hydrated
alumina.
(C) Reaction of powdered one is carried out with hot concentrated NaOH at 473 K - 523 K and 35 - 36
bar pressure.
(D) Electrolysis of Al
2
O
3
is done mixed with Na
3
AlF
6
to produce Al and CO
2
. It is a correct statement.
2021
JEE Advanced 2021 Paper 1 Online
Q1. The correct statement(s) related to the metal extraction processes is (are) :
A. A mixture of ?????? and ?????? undergoes self-reduction to produce ???? and ????
??
B. In the extraction process of copper from copper pyrites, silica is added to produce copper
silicate.
C. Partial oxidation of sulphide ore of copper by roasting, followed by self-reduction produces
blister copper.
D. In cyanide process, zinc powder is utilized to precipitate gold from ???? [???? (???? )
?? ]
Ans: (A,C,D)
Statements (a), (c) and (d) are correct, whereas statement (b) is incorrect. All statements are explained
as follows :
(a) A mixture PbO and PbS reacts as follows:
This reaction is known as self-reduction.
(b) Silica is added to remove impurities of Fe in the form of slag, FeSiO
3
.
(c) CuFeS
2
are in partially oxidised first by roasting and then self-reduction of Cu takes place to produce
blister copper.
(d) Zn powder reacts with Na[Au(CN)
2
] to form gold. This process is called cyanide process.
2Zn + 4Na[Au(CN)
2
] ? 2Na
2
[Zn(CN)
4
] + 4Au
JEE Advanced 2021 Paper 1 Online
Q2. MCQ (More than One Correct Answer) + ?? - ??
A mixture of two salts is used to prepare a solution ?? , which gives the following results :
The correct option(s) for the salt mixture is (are)
A. ???? (????
?? )
?? and ???? (????
?? )
??
B. ???? (????
?? )
?? and ???? (????
?? )
??
Page 4
JEE Advanced Previous Year Questions
(2021-2023): General Principles and
Processes of Isolation of Metals
2023
Multiple Correct Type
JEE Advanced 2023 Paper 1 Online
Q1. The correct statement(s) related to processes involved in the extraction of metals is(are) :
A. Roasting of Malachite produces Cuprite.
B. Calcination of Calamine produces Zincite.
C. Copper pyrites is heated with silica in a reverberatory furnace to remove iron.
D. Impure silver is treated with aqueous ?????? in the presence of oxygen followed by reduction
with zinc metal.
Ans: (B,C,D)
(A) Roasting of malachite
CuCO
3
Cu(OH)
2
?
+O
2
CuO + H
2
O + CO
2
Roasting means that heating of substance in excess of oxygen. So cuprite Cu
2
O is not produced. Hence,
this statement is not correct.
(B) Calcination means heating in absence of air
ZnCO
3
Calamine
?
h?????? ZnO
Zincite
+ CO
2
? Statement is true.
(C)
CuFeS
2
+ O
2
?
h?????? Cu
2
S + FeO + SO
2
FeO + SiO
2
? FeSiO
2
? Statement is true.
(D)
Ag + KCN + O
2
+ 2H
2
O ? 4 K[Ag(CN)
2
] + 4KOH
2 K[Ag(CN)
2
] + Zn ? K
2
[Zn(N)
4
] + 2Ag
Silver is obtained by reaction with Zinc
So, the above statement is true.
2022
JEE Advanced 2022 Paper 2 Online
Q1. The correct option(s) related to the extraction of iron from its ore in the blast furnace
operating in the temperature range ?????? - ???????? ?? is(are)
A. Limestone is used to remove silicate impurity.
B. Pig iron obtained from blast furnace contains about ?? % carbon.
C. Coke (C) converts ????
?? to ???? .
D. Exhaust gases consist of ????
?? and ???? .|
Ans: (A,B,C)
(A) Limestone is added to remove silica as impurity.
(B) Pig iron obtained from blast furnace contains 4% carbon and many other impurities (eg. S, P, Si, Mn)
in small amount.
(C) Coke (C) converts CO
2
in CO.
C + CO
2
? 2CO
(D) Exhaust gases consist of CO and CO
2
.
Hence, (?? , ?? , ?? ) are correct.
JEE Advanced 2022 Paper 1 Online
Q2. The electrochemical extraction of aluminum from bauxite ore involves
A. the reaction of ????
?? ?? ?? with coke (?? ) at a temperature > ???????? °
?? .
B. the neutralization of aluminate solution by passing ????
?? gas to precipitate hydrated alumina
(????
?? ?? ?? · ?? ?? ?? ?? ).
C. the dissolution of ????
?? ?? ?? in hot aqueous ???????? .
D. the electrolysis of ????
?? ?? ?? mixed with ????
?? ?????? ?? to give ???? and ????
?? .
Ans: (B,C,D)
(A) The reduction of Al
2
O
3
with coke (C) at a temperature > 2500
°
C is not carried out due to the
formation of carbides.
(B) It is correct as neutralisation of aluminate solution is done by passing CO
2
gas to precipitate hydrated
alumina.
(C) Reaction of powdered one is carried out with hot concentrated NaOH at 473 K - 523 K and 35 - 36
bar pressure.
(D) Electrolysis of Al
2
O
3
is done mixed with Na
3
AlF
6
to produce Al and CO
2
. It is a correct statement.
2021
JEE Advanced 2021 Paper 1 Online
Q1. The correct statement(s) related to the metal extraction processes is (are) :
A. A mixture of ?????? and ?????? undergoes self-reduction to produce ???? and ????
??
B. In the extraction process of copper from copper pyrites, silica is added to produce copper
silicate.
C. Partial oxidation of sulphide ore of copper by roasting, followed by self-reduction produces
blister copper.
D. In cyanide process, zinc powder is utilized to precipitate gold from ???? [???? (???? )
?? ]
Ans: (A,C,D)
Statements (a), (c) and (d) are correct, whereas statement (b) is incorrect. All statements are explained
as follows :
(a) A mixture PbO and PbS reacts as follows:
This reaction is known as self-reduction.
(b) Silica is added to remove impurities of Fe in the form of slag, FeSiO
3
.
(c) CuFeS
2
are in partially oxidised first by roasting and then self-reduction of Cu takes place to produce
blister copper.
(d) Zn powder reacts with Na[Au(CN)
2
] to form gold. This process is called cyanide process.
2Zn + 4Na[Au(CN)
2
] ? 2Na
2
[Zn(CN)
4
] + 4Au
JEE Advanced 2021 Paper 1 Online
Q2. MCQ (More than One Correct Answer) + ?? - ??
A mixture of two salts is used to prepare a solution ?? , which gives the following results :
The correct option(s) for the salt mixture is (are)
A. ???? (????
?? )
?? and ???? (????
?? )
??
B. ???? (????
?? )
?? and ???? (????
?? )
??
C. ???????? ?? and ???? (????
?? )
??
D. ???? (????
?? )
?? and ???? (????
?? )
??
Ans: (A,B)
Pb(NO
3
)
2
, Bi(NO
3
)
3
and Zn(NO
3
)
2
give white precipitate with dil. NaOH and dil. HCl. Complete reactions
are as follows:
Whereas, AgNO
3
and Hg(NO
3
)
3
give ppt. of different colours.
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