Consider the following reaction.
\(\small{Bauxite\ ore\ +\ NaOH\ (conc.) \xrightarrow[\Delta]{Digester} \underset{Soluble}{(A)}}\)
\((A) \xrightarrow{Fresh\ Al(OH)_3}\ \underset{White}{(B)}\ +\ (C)\)
\({(B)} \xrightarrow[]{\Delta}\ (D)\ +\ H_2O\)
What is the molecular formula of compound D?

1. ${\mathrm{NaAlO}}_2$

2. $\mathrm{Al}{\left(\mathrm{OH}\right)}_3$

3. ${\mathrm{Al}}_2{\mathrm{O}}_3$

4. ${\mathrm{Na}}_2\mathrm{O}$

Consider the following metallurgical process:

Sulphide  \(\xrightarrow[]{\Delta }\)  oxide  \(\xrightarrow[]{\Delta }\)
Impure metal \(\xrightarrow[]{\Delta }\) pure metal

The processes A, B, and C in the above mentioned reaction are, respectively:

1. Calcination, smelting, and electrolysis

2. Roasting, smelting, and electrolysis

3. Calcination, auto reduction, and bessemerisation

4. Roasting, aluminothermic reduction, electrolysis

2MS + 3O₂ → 2MO + 2SO₂
2MO + MS → 3M + SO₂

The metal M in above-mentioned reaction is:

1. Mg

2. Pb

3. Sn

4. Fe

Which of the following is an incorrect match?

1. Kaolinite - Al₂(OH)₄Si₂O₅

2. Cuprite - Cu₂O

3. Siderite - FeCO₃

4. Calamine - ZnSO₄

The substance that acts as a collector in the froth flotation method is:

1. Sodium xenate.           

2. Sodium pyrophosphate.

3. Sodium nitroprusside.

4. Sodium ethyl xanthate. 

The extraction of gold and silver involves leaching with CN^- ion. Silver is later recovered by:

1. Liquation

2. Distillation

3. Zone refining

4. Displacement with Zn

Ellingham's diagram for the formation of ${\mathrm{CO}}_2$ is a straight line in the given graph. This is due to:

1. Increase in entropy during ${\mathrm{CO}}_2$ formation.

2. Decrease in entropy during ${\mathrm{CO}}_2$ formation.

3. Entropy remains constant during ${\mathrm{CO}}_2$ formation.

4. Can not be predicted.

The fundamental principle of froth flotation process is:

In the process of extraction of silver,

silver ore + ${\mathrm{CN}}^{-}+$ ${\mathrm{H}}_2\mathrm{O}\stackrel{{\mathrm{O}}_2}{\to }$ $$ $$ $$ $$ $$ $\left[\mathrm{X}\right]$ $+$ ${\mathrm{OH}}_{}^{-}$

[X] + Zn $\to$ $$[Y] + Ag

[X], and [Y] in the above mentioned reaction are:

1. X= [Ag(CN)${}_2$]^$-$; Y = [Zn(CN)${}_4$]^-2

2. X= [Ag(CN)${}_2$]^-3; Y=[Zn(CN)${}_4$]^-2

3. X= [Ag(CN)${}_2$]^$-$; Y=[Zn(CN)${}_6$]^$-$

4. X=[Ag(CN)${}_4$]^$-$ ; Y= [Zn(CN)${}_4$]^$-$2 

Among the following an iron mineral is:

1. Malachite

2. Cassiterite

3. Pyrolusite

4. Magnetite