In Down's method for the extraction of sodium, the melting point of the electrolyte is lowered by adding

$2\underset{\mathrm{s}}{\mathrm{PbO}} + \underset{\mathrm{s}}{\mathrm{C}} \to 2\underset{\mathrm{s}}{\mathrm{Pb}} + 2\underset{\mathrm{g}}{{\mathrm{CO}}_2}$

Which of the following statements are correct for the above chemical reaction?

(i) Lead is reduced.

(ii) Carbon di oxide is oxidised.

(iii) Carbon is oxidised.

(iv) Lead oxide is reduced

Choose the correct statements about the given chemical reaction: 

$3{\mathrm{MnO}}_2\left(\mathrm{S}\right) + 4\mathrm{Al}\left(\mathrm{S}\right) \to 3\mathrm{Mn}\left(\mathrm{l}\right) + 2{\mathrm{Al}}_2{\mathrm{O}}_3+ \mathrm{Heat}.$

a) Reaction is exothermic.

b) Al is acting as a reducing agent.

c)${\mathrm{MnO}}_2$  is getting reduced.

d) Al is more reactive than Mn

$$\begin{gathered} \mathrm{X}+\mathrm{Y} \to \mathrm{Z}+{\mathrm{SO}}_2 \\ \mathrm{X}+\mathrm{Z}\to \mathrm{Cu}+{\mathrm{SO}}_2 \end{gathered}$$

Identify X, Y and Z:

Give one word or a phrase for the following statement:

• Electrode used as a cathode in electrorefining of impure copper.

During electrolytic production of aluminium, the carbon anodes are replaced from time to time because 

$2\mathrm{Al} + 2{\mathrm{Fe}}_2{\mathrm{O}}_3\to {\mathrm{Al}}_2{\mathrm{O}}_3+2\mathrm{Fe}$

($\mathrm{Al}=27\mathrm{u}, \mathrm{Fe}=56\mathrm{u}, \mathrm{O}=16\mathrm{u}$ are the atomic masses)

How much of Iron, we can get if 54 kg of Aluminium is used?

Write the steps involved in the extraction of pure metals in the middle of the activity series from their carbonate ores.