Principles of Metallurgy and Extraction

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JEE Advanced 2020

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

Al_{2} O_{3}

precipitates, when

CO_{2}

is bubbled through a solution of sodium aluminate.

(B)

Addition of

Na_{3} AlF_{6}

lowers the melting point of alumina.

(C)

CO_{2}

is evolved at the anode during electrolysis.

(D)

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

JEE Advanced 2022

LEVELJEE Main

The correct option(s) related to the extraction of iron from its ore in the blast furnace operating in the temperature range $900 - 1500 K$ is(are)

* Multiple Correct Options

(A)

Limestone is used to remove silicate impurity.

(B)

Pig iron obtained from blast furnace contains about

4%

carbon.

(C)

Coke (C) converts

CO_{2}

CO

(D)

Exhaust gases consist of

NO_{2}

and

CO

JEE Advanced 2014

LEVELJEE Main

Upon heating with $Cu_{2} S$ , the reagent(s) that give copper metal is/are

(A)

CuFeS_{2}

(B)

CuO

(C)

Cu_{2} O

(D)

CuSO_{4}

JEE Advanced 2023

LEVELJEE Main

The correct statement(s) related to processes involved in the extraction of metals is(are)

* Multiple Correct Options

(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 KCN in the presence of oxygen followed by reduction with zinc metal.

JEE Advanced 2018

LEVELJEE Main

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

JEE Advanced 2019

LEVELJEE Main

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).

* Multiple Correct Options

(A)

T

Zn

(B)

R

[Au (CN)_{4}]^{-}

(C)

Z

[Zn (CN)_{4}]^{2 -}

(D)

Q

O_{2}

JEE Advanced 2021

LEVELJEE Main

The correct statement(s) related to the metal extraction processes is(are)

* Multiple Correct Options

(A)

A mixture of PbS and PbO undergoes self-reduction to produce Pb and SO2.

(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 Na[Au(CN)2].

JEE Advanced 2016

LEVELJEE Main

Extraction of copper from copper pyrite ( $CuFeS_{2}$ ) involves

* Multiple Correct Options

(A)

crushing followed by concentration of the ore by froth-flotation

(B)

removal of iron as slag

(C)

self-reduction step to produce 'blister copper' follwoing evolution of

SO_{2}

(D)

refining of 'blister copper' by carbon reduction

JEE Advanced 2022

LEVELJEE Main

The electrochemical extraction of aluminum from bauxite ore involves.

* Multiple Correct Options

(A)

the reaction of

Al_{2} O_{3}

with coke (C) at a temperature

> 250 0^{\circ} C

(B)

the neutralization of aluminate solution by passing

CO_{2}

gas to precipitate hydrated alumina (

Al_{2} O_{3} \cdot 3 H_{2} O

(C)

the dissolution of

Al_{2} O_{3}

in hot aqueous NaOH.

(D)

the electrolysis of

Al_{2} O_{3}

mixed with

Na_{3} AlF_{6}

to give Al and

CO_{2}

JEE Main 2020

LEVELJEE Main

The processes of calcination and roasting in metallurgical industries, respectively, can lead to

(A)

global warming and acid rain

(B)

global warming and photochemical smog

(C)

photochemical smog and ozone layer depletion

(D)

photochemical smog and global warming

JEE Main 2021

LEVELJEE Main

Given below are two statements. Statement I The choice of reducing agent for metals extraction can be made by using Ellingham diagram, a plot of $Δ G$ vs temperature. Statement II The value of $Δ S$ increases from left to right in Ellingham diagram. In the light of the above statements, choose the most appropriate answer from the options given below.

(A)

Both statement I and statement II are true.

(B)

Statement I is false but statement II is true.

(C)

Both statement I and statement II are false.

(D)

Statement I is true but statement II is false.

JEE Main 2021

LEVELJEE Main

The process that involves the removal of sulphur from the ores is

The incorrect statement is

(A)

bronze is an alloy of copper and tin.

(B)

cast iron is used to manufacture wrought iron.

(C)

german silver is an alloy of zinc, copper and nickel.

(D)

brass is an alloy of copper and nickel.

JEE Main 2021

LEVELJEE Main

Match List I with List II : (Both having metallurgical terms) \begin{array}{ll} \text{List I} & \text{List II} \\ \text{(A) Concentration of Ag ore} & \text{I. Reverberatory furnace} \\ \text{(B) Blast furnace} & \text{II. Pig iron} \\ \text{(C) Blister copper} & \text{III. Leaching with dilute NaCN solution} \\ \text{(D) Froth floatation method} & \text{IV. Sulphide ores} \end{array} Choose the correct answer from the options given below.

(A)

\to

III, B

\to

II, C

\to

I, D

\to

(B)

\to

III, B

\to

IV, C

\to

I, D

\to

(C)

\to

IV, B

\to

I, C

\to

III, D

\to

(D)

\to

IV, B

\to

III, C

\to

II, D

\to

JEE Main 2021

LEVELJEE Main

Given below are two statements. Statement I Sphalerite is a sulphide ore of zinc and copper glance is a sulphide ore of copper. Statement II It is possible to separate two sulphide ores by adjusting proportion of oil to water or by using ‘depressants’ in a froth flotation method. Choose the most appropriate answer from the options given below.

(A)

Statement I is true but statement II is false.

(B)

Both statement I and statement II are true.

(C)

Statement I is false but statement II is true.

(D)

Both statement I and statement II are false.

JEE Main 2019

LEVELJEE Main

The pair that does not require calcination is

(A)

ZnO

and

MgO

(B)

ZnO

and

Fe_{2} O_{3} \cdot x H_{2} O

(C)

ZnCO_{3}

and

CaO

(D)

Fe_{2} O_{3}

and

CaCO_{3} \cdot MgCO_{3}

JEE Main 2019

LEVELJEE Main

With respect to an ore, Ellingham diagram helps to predict the feasibility of its

vapour phase refining

An Ellingham diagram provides information about

(A)

the kinetics of the reduction process.

(B)

the pressure dependence of the standard electrode potentials of reduction reactions involved in the extraction of metals.

(C)

the temperature dependence of the standard Gibbs energies of formation of some metal oxides.

(D)

the conditions of pH and potential under which a species is thermodynamically stable.

JEE Main 2021

LEVELJEE Advanced

The point of intersection and sudden increase in the slope, in the diagram given below, respectively, indicates.

(A)

Δ G = 0

and melting or boiling point of the metal oxide

(B)

Δ G > 0

and decomposition of the metal oxide

(C)

Δ G < 0

and decomposition of the metal oxide

(D)

Δ G = 0

and reduction of the metal oxide

JEE Main 2019

LEVELJEE Main

In the Hall-Heroult process, aluminium is formed at the cathode. The cathode is made out of

Consider two chemical reactions (A) and (B) that take place during metallurgical process : (A) $ZnCO_{3} (s) Δ ZnO (s) + CO_{2} (g)$ (B) $2 ZnS (s) + 3 O_{2} (g) Δ 2 ZnO (s) + 2 SO_{2} (g)$ The correct option of names given to them respectively is

(A)

(A) is calcination and (B) is roasting

(B)

Both (A) and (B) are producing same product so both are roasting

(C)

Both (A) and (B) are producing same product so both are calcination

(D)

(A) is roasting and (B) is calcination

LEVELJEE Main

Which one of the following ores is best concentrated by froth-floatation method ?

Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) Aluminium is extracted from bauxite by the electrolysis of molten mixture of $Al_{2} O_{3}$ with cryolite. Reason (R) The oxidation state of Al in cryolite is $+ 3$ . In the light of the above statements, choose the most appropriate answer from the options given below.

(A)

(A) is true but (R) is false

(B)

(A) is false but (R) is true.

(C)

Both (A) and (R) are true and (R) is the correct explanation of (A).

(D)

Both (A) and (R) are true but (R) is not the correct explanation of (A).

JEE Main 2021

LEVELJEE Main

Ellingham diagram is a graphical representation of

(A)

Δ G

T

(B)

Δ H

T

(C)

Δ G

p

(D)

(Δ G - T Δ S)

T

JEE Main 2019

LEVELJEE Main

The correct statement regarding the given Ellingham diagram is

(A)

80 0^{\circ} C

, Cu can be used for the extraction of Zn from ZnO

(B)

140 0^{\circ} C

, Al can be used for the extraction of Zn from ZnO

(C)

50 0^{\circ} C

, coke can be used for the extraction of Zn from ZnO

(D)

Coke cannot be used for the extraction of Cu from

Cu_{2} O

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

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The correct statement(s) related to processes involved in the extraction of metals is(are)

The correct statement(s) related to the metal extraction processes is(are)

.math-text-wrapper .katex { font-size: 1.05em !important; } .math-text-wrapper .katex-display { margin: 1rem 0 !important; } Extraction of copper from copper pyrite (CuFeS2​) involves

The electrochemical extraction of aluminum from bauxite ore involves.

The processes of calcination and roasting in metallurgical industries, respectively, can lead to

The process that involves the removal of sulphur from the ores is

The incorrect statement is

The pair that does not require calcination is

With respect to an ore, Ellingham diagram helps to predict the feasibility of its

An Ellingham diagram provides information about

The point of intersection and sudden increase in the slope, in the diagram given below, respectively, indicates.

In the Hall-Heroult process, aluminium is formed at the cathode. The cathode is made out of

Which one of the following ores is best concentrated by froth-floatation method ?

Ellingham diagram is a graphical representation of

The correct statement regarding the given Ellingham diagram is

The correct option(s) related to the extraction of iron from its ore in the blast furnace operating in the temperature range $900 - 1500 K$ is(are)

Upon heating with $Cu_{2} S$ , the reagent(s) that give copper metal is/are

Extraction of copper from copper pyrite ( $CuFeS_{2}$ ) involves