Zone refining is based on the principle that ___________.
 

1.	Impurities of low boiling metals can be separated by distillation.
2.	Impurities are more soluble in molten metal than in solid metal.
3.	Different components of a mixture are differently adsorbed on an adsorbent.
4.	Vapors of the volatile compounds can be decomposed in pure metal.

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

Answer the question on the basis of Figure

Choose the correct option of temperature at which carbon reduces FeO to iron and produces CO.

1.  Below temperature at point A.

2.  Approximately at the temperature corresponding to point A.

3.  Above temperature at point A but below the temperature at point D.

4.  Above temperature at point A.

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

         Column I            Column II

(A) Pendulum         (1) Chrome steel

(B) Malachite          (2) Nickel steel

(C) Calamine          (3) ${\mathrm{Na}}_3{\mathrm{AlF}}_6$

(D) Cryolite            (4) ${\mathrm{CuCO}}_3.\mathrm{Cu} {\left(\mathrm{OH}\right)}_2$

                             (5) ${\mathrm{ZnCO}}_3$

1.  A (1)  B (2)  C (3)  D (4)

2.  A (2)  B (4)  C (5)  D (3)

3.  A (2)  B (3)  C (4)  D (5)

4.  A (4)  B (5)  C (3)  D (2)

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

1. A =(1); B=(2); C=(4); D=(5)

2. A=(4); B=(3); C=(1); D=(2)

3. A=(3); B=(4); C=(2); D=(1)

4. A=(5); B=(4); C=(3); D=(2)

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

     Column I             Column II

(A) Sapphire           (1) ${\mathrm{Al}}_2{\mathrm{O}}_3$
(B) Sphalerite         (2) NaCN
(C) Depressant       (3) Co
(D) Corundum        (4) ZnS
                             (5) ${\mathrm{Fe}}_2{\mathrm{O}}_3$

1.  A (3)  B (4)  C (2)  D (1)

2.  A (5)  B (4)  C (3)  D (2)

3.  A (2)  B (3)  C (4)  D (5)

4.  A (1)  B (2)  C (3)  D (4)

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

Which of the following is not a mineral of aluminium?

Serpek’s method involves the heating of bauxite with

1. NaOH

2. Na₂CO₃

3. N₂ +C

4. CaCO₃