Identify the incorrect statement

1.	The scientific and technological process used for isolation of the metal from its ore is known as metallurgy
2.	Minerals are naturally occurring chemical substances in the earth's crust
3.	Ores are minerals that may contain a metal
4.	Gangue is an ore contaminated with undesired materials

 

In the conversion of Zinc ore to zinc metal, the process of roasting involves

1.  ${\mathrm{ZnCO}}_3 \stackrel{}{\to } \mathrm{ZnO}$

2.  $\mathrm{ZnO} \stackrel{}{\to } {\mathrm{ZnSO}}_4$

3.  $\mathrm{ZnS} \stackrel{}{\to } \mathrm{ZnO}$

4.  $\mathrm{ZnS} \stackrel{}{\to } {\mathrm{ZnSO}}_4$

The extraction of silver is achieved by the initial complexation of the ore (Argentine) with X followed by reduction with Y. X and Y respectively are 

1.  ${\mathrm{CN}}^{-}$ and Zn

2.  ${\mathrm{CN}}^{-}$ and Cu

3.  ${\mathrm{Cl}}^{-}$ and Zn

4.  ${\mathrm{Br}}^{-}$ and Zn

Van Arkel method of purification of metals involves converting the metal to a

1. Volatile compound

2. Volatile unstable compound

3. Non-volatile stable compound

4. Non-volatile unstable compound

Which of the following is correct?

I.  $∆$G$°$ for reaction (i) is more negative at T < 1125K

II.  $∆$G$°$ for the reduction of CO is more negative at T < 1125K

III.  ${\mathrm{H}}_2$ is a better reducing agent at T < 1125K

IV.  ${\mathrm{H}}_2$ is a better reducing agent at T > 1125K

1.  I and II

2.  I and III

3.  III only

4.  I and IV

Which of the following reactions is an example of auto reduction?

1.  ${\mathrm{Fe}}_3{\mathrm{O}}_4 + 4\mathrm{CO} \stackrel{}{\to } 3\mathrm{Fe} + 4{\mathrm{CO}}_2$

2.  ${\mathrm{Cu}}_2\mathrm{O} + \mathrm{C} \stackrel{}{\to } 2\mathrm{Cu} + \mathrm{CO}$

3.  ${\mathrm{Cu}}^{2+} \left(\mathrm{aq}\right) + \mathrm{Fe} \left(\mathrm{s}\right) \stackrel{}{\to } \mathrm{Cu} \left(\mathrm{s}\right) + {\mathrm{Fe}}^{2+}\left(\mathrm{aq}\right)$

4.  ${\mathrm{Cu}}_2\mathrm{O} + \frac{1}{2} {\mathrm{Cu}}_2\mathrm{S} \stackrel{}{\to } 3\mathrm{Cu} + \frac{1}{2} {\mathrm{SO}}_2$

A number of elements are available in earth’s crust but most abundant elements are ____________.

1.  Al and Fe

2.  Al and Cu

3.  Fe and Cu

4.  Cu and Ag

Zone refining is based on the principle that ___________.
 

In the metallurgy of aluminium ________________.

Electrolytic refining is used to purify which of the following metals?

1.  Cu and Zn

2.  Ge and Si

3.  Zr and Ti

4.  Zn and Hg