Metallurgy – JEE Advanced Previous Year Questions with Solutions

Metallurgy JEE Advanced Previous Year Questions with Solutions have been crafted for students and JEE aspirants to familiarize themselves with the actual entrance examination test paper. The set of questions given here will enable students in understanding the type of questions that can be asked in the exam, the difficulty level and the important topics. After going through and practising these Metallurgy JEE Advanced Previous Year Questions with Solutions students will further be able to easily map out their strong and weak areas and prepare accordingly.

Additionally, the meticulously prepared solutions will clarify all the doubts while solving the papers. As candidates get more and more familiar with the question types asked in the real exam, it will become very easy for each student to prepare and enhance their study hours. Students will also be able to access the Metallurgy JEE Advanced Previous Year Questions with Solutions PDF below.

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JEE Advanced Previous Year Questions on Metallurgy

Question 1. Calamine, malachite, magnetite and cryolite, respectively are:

A. ZnSO₄, CuCO₃, Fe₂O₃, AlF3

B. ZnSO₄, Cu(OH)₂, Fe₃O₄, Na3AlF6

C. ZnCO₃, CuCO₃•Cu(OH)₂, Fe₃O₄, Na₃AlF₆

D. ZnCO₃, CuCO₃, Fe₂O₃, Na₃AlF₆

Solution: (C)

Calamine is an ore of zinc, malachite is an ore of copper, magnetite is an ore of iron and cryolite is an ore of aluminium.

Calamine – ZnCO₃

Malachite – CuCO₃•Cu(OH)₂

Magnetite – Fe₃O₄

Cryolite – Na₃AlF₆

Question 2. Galena (an ore) is partially oxidized by passing air through it at high temperatures. After some time, the passage of air is stopped, but the heating is continued in a closed furnace such that the contents undergo self-reduction. The weight (in kg) of Pb produced per kg of O₂ consumed is ______. (Atomic weights in g mol^-1 : O = 16, S = 32, Pb = 207)

Solution: (6.47)

The reaction can be as follows:

PbS + O₂ → Pb + SO₂

Moles of PB = Moles of O₂ = 1000 / 32 mol

∴ Mass of Pb = 1000 / 32 × 207 g = 207 / 32 kg = 6.47 kg

OR

So, 3 mol of O₂ gives 3 mol of Pb

Thus, in other words, 96 kg of O₂ gives 621 kg of Pb.

So, 1 kg of O₂ will give 621 / 96 = 6.47 kg

Question 3. Which among the following statement(s) is(are) true for the extraction of aluminium from bauxite?

A. Hydrated Al₂O₃ precipitates when CO₂ is bubbled through a solution of sodium aluminate.

B. Addition of Na₃AlF₆ lowers the melting point of alumina.

C. CO₂ is evolved at the anode during electrolysis.

D. The cathode is a steel vessel with a lining of carbon.

Solution: (A, B, C, D)

A) Extraction of aluminium (Hall’s process and Hall Heroult’s electrolytic cell):

The process involved in the extraction of aluminium is Hall Heroult’s process.

During the process, Al₂O₃ is obtained as a precipitate.

When CO₃ is bubbled through a solution of sodium aluminate.

The reaction is given as:

2Na[Al(OH)₄]_(aq.) + CO₂ → Na₂CO₃ + H₂O + 2Al(OH)₃ (↓) or Al₂O₃.2H₂O (ppt)

B) Electrolytic reduction of pure alumina takes place in a steel box with a lining of carbon (cathode) with cryolite (Na₃AlF₆) and fluorspar (CaF₂) which lowers the melting point and increases the conductivity of the electrolyte.

C) Electrolysis process in Hall’s process:

Graphite rods acts as anode:

At cathode:

Al⁺³ + 3e^– → Al

At anode: The oxygen liberated at the anode reacts with the carbon of the anode to produce CO and CO₂.

C + O^2- → CO + 2e^–

C + 2O^2- → CO₂ + 4e^–

D) Here the cathode is a steel vessel with a lining of carbon.

Question 4. The cyanide process of gold extraction involves leaching out gold from its ore with CN– in the presence of Q in water to form R. Subsequently, R is treated with T to obtain Au and Z. Choose the correct option(s)

A. Q is O₂

B. R is [Au(CN)₄]^–

C. Z is [Zn(CN)₄]^2-

D. T is Zn

Solution: (A, C and D)

Extraction of gold is usually done by leaching with dil. solution of NaCN in the presence of air (O₂).

Question 5. Extraction of copper from copper pyrite CuFeS₂ involves

A. Crushing followed by concentration of the ore by froth-floatation

B. Removal of Iron as slag

C. Self-reduction step to produce ‘blister copper’ following the evolution of SO₂

D. Refining of ‘blister copper’ by carbon reduction

Solution: (A, B and C)

The correct option is C – Self-reduction step to produce ‘blister copper’ following the evolution of SO2₂

First, the ore is ground into a fine powder through crushing and grinding. Since the ore is a sulphide ore, it is concentrated using froth-floatation.

Eventually, the iron in CuFeS₂ is removed as FeSiO₃ – as slag.

The mixture of Cu₂S and Cu₂O undergoes self-reduction to yield blister copper (there are blisters because of the evolution of SO₂ and other gases).

It is then refined electrolytically to get very pure metallic copper.

Question 6. Match the anionic species given in Column-I that are present in the ore(s) given in Column-II:

A. A → P, Q, S; B → T; C → Q, R; D → R (P)

B. A → Q, S; B → S; C → Q; D → P

C. A → P, S; B → Q; C → Q, T; D → P

D. A → P, Q; B → R; C → Q, R; D → T

Solution: (A)

A → P, Q, S; B → T; C → Q, R; D → R (P)

Siderite – FeCO₃ (Q)

Malachite – CuCO₃.Cu(OH)₂ (R)

Bauxite – AlOx(OH)_{3 – 2x} (S)

Calamine – ZnCO₃ (T)

Argentite – Ag₂S

Question 7. Copper is purified by electrolytic refining of blister copper. The correct statement(s) about this process is (are) –

A. Impure Cu strip is used as cathode

B. Acidified aqueous CuSO₄ is used as an electrolyte

C. Pure Cu deposits at the cathode

D. Impurities settle as anode-mud

Solution: (B, C and D)

During purification of copper by electrolytic refining of blister copper,

(B) The electrolyte used is acidified aqueous copper sulphate solution. Hence, option (B) is correct.

(C) Pure Cu transfers from anode to cathode and deposits at the cathode. Hence, option (C) is correct.

(D) Impurities like Fe, Zn, Ni, Co etc. dissolve in the solution as sulphates and others like Au and Ag settle as anode-mud. Hence, option (D) is correct.

Question 8. Upon heating with Cu₂S, the reagent(s) that give copper metal is/are:

A. CuFeS₂

B. CuO

C. Cu₂O

D. CuSO₄

Solution: (B, C and D)

Question 9. Sulfide ores are common for metals.

A. Ag, Cu and Pb

B. Ag, Cu and Sn

C. Ag, Mg and Pb

D. Al, Cu and Pb

Solution: (A)

Sulphide ores of Ag, Pb and Cu are, respectively, Argentite (Ag₂S), Galena (PbS) and Copper glance (Cu₂S).

Question 10. The carbon-based reduction method is not used for the extraction of:

A. Tin from SnO₂

B. Iron from Fe₂O₃

C. Aluminium from Al₂O₃

D. Magnesium from CaCO₃

Solution: (C and D)

AI has a greater affinity for oxygen, hence oxide is not reduced by carbon. Aluminium is extracted by the Hall-Heroult process where Al₂O₃ is mixed with fluorspar and cryolite and then subjected to fused electrolysis (non-aqueous).

MgO and CaO (formed in the calcination from carbonates) are stable species and not reduced by carbon.

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Metallurgy – Previous Year Questions