NEET > General Principles and Processes of Isolation of Elements

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Q 1.

Correct4

Incorrect-1

Extraction of gold and silver involves leaching with {tex} \mathrm { CN } ^ { - } {/tex} ion. Silver is later recovered by

A

distillation

B

zone refining

displacement with {tex} \mathrm { Zn } {/tex}

D

liquation

Explanation

Q 2.

Correct4

Incorrect-1

Match items of Column I with the items of Column II and assign the correct code:

A

{tex} \mathrm {{A}- {(i)}, {B} - {(ii)}, {C} - {(iii)}, D-{(iv)}}{/tex}

B

{tex} \mathrm {{A}- {(iii)}, {B} - {(iv)}, {C} - {(v)}, D-{(i)}}{/tex}

{tex} \mathrm {{A}- {(iv)}, {B} - {(ii)}, {C} - {(iii)}, D-{(i)}}{/tex}

D

{tex} \mathrm {{A}- {(ii)}, {B} - {(iii)}, {C} - {(i)}, D-{(v)}}{/tex}

Explanation

Q 3.

Correct4

Incorrect-1

In the extraction of copper from its sulphide ore, the metal is finally obtained by the reduction of cuprous oxide with

A

carbon monoxide

copper (I) sulphide

C

sulphur dioxide

D

iron(II) sulphide.

Explanation

Q 4.

Correct4

Incorrect-1

"Metals are usually not found as nitrates in their ores." Out of the following two (I and II) reasons which is/are true for the above observation?
{tex}\mathrm I{/tex}. Metal nitrates are highly unstable.
{tex}\mathrm {II}{/tex}. Metal nitrates are highly soluble in water.

I is false but II is true

B

I is true but II is false.

C

I and II are true.

D

I and II are false

Explanation

Q 5.

Correct4

Incorrect-1

Roasting of sulphides gives the gas {tex}X{/tex} as a byproduct. This is a colourless gas with choking smell of burnt sulphur and causes great damage to respiratory organs as a result of acid rain. Its aqueous solution is acidic, acts as a reducing agent and its acid has never been isolated.
The gas {tex} X {/tex} is

A

{tex} \mathrm { CO } _ { 2 } {/tex}

B

{tex} \mathrm { SO } _ { 3 } {/tex}

C

{tex} \mathrm { H } _ { 2 } \mathrm { S } {/tex}

{tex} \mathrm { SO } _ { 2 } {/tex}

Explanation

Q 6.

Correct4

Incorrect-1

The metal oxide which cannot be reduced to metal by carbon is

{tex} \mathrm { Al } _ { 2 } \mathrm { O } _ { 3 } {/tex}

B

{tex} \mathrm { PbO } {/tex}

C

{tex} \mathrm{ZnO}{/tex}

D

{tex} \mathrm { Fe } _ { 2 } \mathrm { O } _ { 3 } {/tex}

Explanation

Q 7.

Correct4

Incorrect-1

Aluminium is extracted from alumina{tex} \left( \mathrm { Al } _ { 2 } \mathrm { O } _ { 3 } \right) {/tex} by electrolysis of a molten mixture of

A

{tex} \mathrm { Al } _ { 2 } \mathrm { O } _ { 3 } + \mathrm { HF } + \mathrm { NaAlF } _ { 4 } {/tex}

B

{tex} \mathrm { Al } _ { 2 } \mathrm { O } _ { 3 } + \mathrm { CaF } _ { 2 } + \mathrm { NaAlF } _ { 4 } {/tex}

{tex} \mathrm { Al } _ { 2 } \mathrm { O } _ { 3 } + \mathrm { Na } _ { 3 } \mathrm { AlF } _ { 6 } + \mathrm { CaF } _ { 2 } {/tex}

D

{tex} \mathrm { Al } _ { 2 } \mathrm { O } _ { 3 } + \mathrm { KF } + \mathrm { Na } _ { 3 } \mathrm { AlF } _ { 6 } {/tex}

Explanation

Q 8.

Correct4

Incorrect-1

Which one of the following is a mineral of iron?

A

Malachite

B

Cassiterite

C

Pyrolusite

Magnetite

Explanation

Q 9.

Correct4

Incorrect-1

Which of the following elements is present as the impurity to the maximum extent in the pig iron?

A

Manganese

Carbon

C

Silicon

D

Phosphorus

Explanation

Q 10.

Correct4

Incorrect-1

Which of the following pairs of metals is purified by van Arkel method?

A

Ga and In

Zr and Ti

C

Ag and Au

D

Ni and Fe

Explanation

Q 11.

Correct4

Incorrect-1

The following reactions take place in the blast furnace in the preparation of impure iron. Identify the reaction pertaining to the formation of the slag.

A

{tex} \mathrm { Fe } _ { 2 } \mathrm { O } _ { 3 ( s ) } + 3 \mathrm { CO } _ { ( \mathrm { g } ) } \rightarrow 2 \mathrm { Fe } _ { ( l ) } + 3 \mathrm { CO } _ { 2 ( \mathrm { g } ) } {/tex}

B

{tex} \mathrm { CaCO } _ { 3 ( \mathrm { s } ) } \rightarrow \mathrm { CaO } _ { ( \mathrm { s } ) } + \mathrm { CO } _ { 2 ( \mathrm { g } ) } {/tex}

{tex} \mathrm { CaO } _ { ( \mathrm { s } ) } + \mathrm { SiO } _ { 2 ( \mathrm { s } ) } \rightarrow \mathrm { CaSiO } _ { 3 ( \mathrm { s } ) } {/tex}

D

{tex} 2 \mathrm { C } _ { ( s ) } + \mathrm { O } _ { 2 ( \mathrm { g } ) } \rightarrow 2 \mathrm { CO } _ { ( \mathrm { g } ) } {/tex}

Explanation

Q 12.

Correct4

Incorrect-1

Sulphide ores of metals are usually concentrated by froth floatation process. Which one of the following sulphide ores offer an exception and is concentrated by chemical leaching?

A

Galena

B

Copper pyrite

C

Sphalerite

Argentite

Explanation

Q 13.

Correct4

Incorrect-1

Which of the following statements, about the advantage of roasting of sulphide ore before reduction is not true?

A

The {tex} \Delta G _ { f } ^ { \circ } {/tex} of the sulphide is greater than those for {tex} \mathrm { CS } _ { 2 } {/tex} and {tex} \mathrm { H } _ { 2 } \mathrm { S } {/tex} .

B

The {tex} \Delta G _ { f } ^ { \rho } {/tex} is negative for roasting of sulphide ore to oxide.

C

Roasting of the sulphide to the oxide is thermodynamically feasible.

Carbon and hydrogen are suitable reducing agents for metal sulphides.

Explanation

Q 14.

Correct4

Incorrect-1

The method of zone refining of metals is based on the principle of

A

greater mobility of the pure metal than that of the impurity

B

higher melting point of the impurity than that of the pure metal

C

greater noble character of the solid metal than that of the impurity

greater solubility of the impurity in the molten state than in the solid

Explanation

Q 15.

Correct4

Incorrect-1

Cassiterite is an ore of

A

{tex} \mathrm { Sb } {/tex}

B

{tex} \mathrm { Ni} {/tex}

C

{tex} \mathrm { Mn } {/tex}

{tex} \mathrm { Sn } {/tex}

Explanation

Q 16.

Correct4

Incorrect-1

Purification of aluminium, by electrolytic refining, is known as

Hoope's process

B

Bayer's process

C

Hall's process

D

Serpeck's process

Explanation

Q 17.

Correct4

Incorrect-1

Calcium is obtained by

A

reduction of calcium chloride with carbon

electrolysis of molten anhydrous calcium chloride

C

roasting of limestone

D

electrolysis of solution of calcium chloride in {tex} \mathrm { H } _ { 2 } \mathrm { O } {/tex}

Explanation

Q 18.

Correct4

Incorrect-1

Bronze is a mixture of

A

{tex} \mathrm { Pb } + \mathrm { Sn } {/tex}

{tex} \mathrm { Cu } + \mathrm { Sn } {/tex}

C

{tex} \mathrm { Cu } + \mathrm { Zn } {/tex}

D

{tex} \mathrm { Pb } + \mathrm { Zn } {/tex}

Explanation

Q 19.

Correct4

Incorrect-1

Which of the following pair is incorrectly matched?

A

Magnetite - {tex} \mathrm { Fe } _ { 3 } \mathrm { O } _ { 4 } {/tex}

B

Copper glance - {tex}\mathrm { Cu } _ { 2 } \mathrm { S } {/tex}

C

Calamine - {tex}\mathrm { ZnCO } _ { 3 } {/tex}

Zincite - {tex}\mathrm {ZnS}{/tex}

Explanation

Q 20.

Correct4

Incorrect-1

Which of the following factors is of no significance for roasting sulphide ores to the oxides and not subjecting the sulphide ores to carbon reduction directly?

A

Metal sulphides are thermodynamically more stable than {tex} \mathrm { CS } _ { 2 } {/tex}

B

{tex} \mathrm { CO } _ { 2 } {/tex} is thermodynamically more stable than {tex} \mathrm { CS } _ { 2 } {/tex}

Metal sulphides are less stable than the corresponding oxides

D

{tex} \mathrm { CO } _ { 2 } {/tex} is more volatile than {tex} \mathrm { CS } _ { 2 } {/tex}

Explanation

Q 21.

Correct4

Incorrect-1

Aluminothermic process is used for the extraction of metals, whose oxides are

A

fusible

not easily reduced by carbon

C

not easily reduced by hydrogen

D

strongly basic.

Explanation

Q 22.

Correct4

Incorrect-1

Which reagent is used in Bayer's process?

A

{tex} \mathrm { Na } _ { 2 } \mathrm { CO } _ { 3 } {/tex}

B

Carbon

{tex} \mathrm { NaOH } {/tex}

D

Silica

Explanation

Q 23.

Correct4

Incorrect-1

Which of the following reaction takes place in blast furnace during extraction of copper?

A

{tex} 2 \mathrm { Cu } _ { 2 } \mathrm { S } + 3 \mathrm { O } _ { 2 } \longrightarrow 2 \mathrm { Cu } _ { 2 } \mathrm { O } + 2 \mathrm { SO } _ { 2 } {/tex}

B

{tex} 2 \mathrm { FeS } + 3 \mathrm { O } _ { 2 } \longrightarrow 2 \mathrm { FeO } + 2 \mathrm { SO } _ { 2 } {/tex}

C

{tex} 2 \mathrm { Cu } _ { 2 } \mathrm { O } + \mathrm { Cu } _ { 2 } \mathrm { S } \longrightarrow 6 \mathrm { Cu } + \mathrm { SO } _ { 2 } {/tex}

All of these

Explanation

Q 24.

Correct4

Incorrect-1

When an aqueous solution of sodium chloride is electrolysed using platinum electrodes, the ion discharged at the electrodes are

A

sodium and hydrogen

B

sodium and chloride

hydrogen and chloride

D

hydroxyl and chloride

Explanation

Q 25.

Correct4

Incorrect-1

Which of the following elements is present as the impurity to the maximum extent in the pig iron?

A

Manganese

Carbon

C

Silicon

D

Phosphorus