Compound (D) is

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

$\mathrm{Sulphide} \stackrel{∆}{\to } \mathrm{oxide} \stackrel{∆}{\to } \mathrm{impure} \mathrm{metal} \stackrel{∆}{\to } \mathrm{pure} \mathrm{metal}$

The various processes A, B, and C respectively

1.  Calcination, smelting, and electrolysis

2.  Roasting, smelting, and electrolysis

3.  Calcination, auto reduction, and bassemetisation

4.  Roasting, aluminothermic reduction, electrolysis

NaCN is a depressant that is used: 

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.

Which of the following statements is correct regarding the slag obtained during the

extraction of a metal like copper or iron?

(1)  The slag is lighter and has a lower melting point than the metal

(2)  The slag is heavier and has a lower melting point than the metal

(3)  The slag is lighter and has a higher melting point than the metal

(4)  The slag is heavier and has a higher melting point than the metal

The process of bringing the metal or its ore into solution by the action of a suitable

chemical reagent followed by extraction of the metal either by electrolysis or by a

the suitable precipitating agent is called

1.  Electrometallurgy

2.  Hydrometallurgy

3.  Electrorefining

4.  Zone refining

Why is roasting important in the iron metallurgy process?  

Identify the metal M, which has the following extraction principle.

$\mathrm{MS} + {\mathrm{O}}_2 \stackrel{}{\to } {\mathrm{MO\; +SO2 }}_{}{\mathrm{MO}}_{} + \mathrm{MS} \stackrel{}{\to } 2\mathrm{M} + 2{\mathrm{SO}}_2$

1.  Mg

2.  Pb

3.  Sn

4.  Fe

The process of converting hydrated alumina into anhydrous alumina is called

1. Roasting

2. Smelting

3. Dressing

4. Calcination

Mg in the Kroll process acts as

(1)  Reducing agent

(2)  Oxidizing agent

(3)  Oxidizing agent at low temperature

(4)  Reducing agent at low temperature