Limestone is used as a flux in the extraction of

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:

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

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