Question

(a) Name the chemical compound which is electrolysed in molten state to obtain aluminium metal. Which gas is evolved during this process?
(b) Name the chemical compound which is electrolysed in molten state to obtain sodium metal. Which gas is produced in this process?
(c) Name the gas produced when calamine ore is calcined.
(d) Name the gas evolved when cinnabar ore is roasted.

Answer 1

Answer:

a)Aluminium oxide is electrolysed in molten state to obtain aluminium metal. Oxygen gas is evolved during this process.

b)The chemical compund electrolysed is sodium chloride in molten state to obtain sodium metal. During the process chlorine gas is evolved

c)Carbon dioxide is produced when calamine ore is calcined.

D)Sulphur dioxide gas is evolved when cinnabar ore is roasted

Answer 2

(a) The electrolysed chemical compound is aluminium oxide, which on electrolysation obtains aluminium metal. During the process, oxygen gas is evolved.  

(b) In the molten state, sodium chloride is electrolysed to obtain sodium metal. In this process, chlorine gas is evolved.

(c) When calamine ore is calcined, carbon dioxide is produced.

(d) When cinnabar ore is roated, sulphur oxide gas is produced.

Explanation:

(a) The equation for aluminium oxide decomposition is:

$2 A l_{2} O_{2}(l) \rightarrow 4 A l(l)+3 O_{2}(g)$

$Aluminium oxide\ Aluminium \ Oxygen$

(b) The equation for evolving chlorine gas during decomposition is:

$2 \mathrm{NaCL}(l) \rightarrow 2 \mathrm{Na}(a)+\mathrm{Cl}_{2}(g)$

$Sodium chloride\ sodium\ chlorine$

(c) The equation of calcification is:

$\mathrm{ZnCO}_{3}(s) \rightarrow \mathrm{ZnO}(a)+\mathrm{CO}_{2}(g)$

$Zinc carbonate \quad Zinc Oxide \quad Carbon dioxide$

(d) The reduction reaction is shown as:

$2 \mathrm{HgS}(s)+3 \mathrm{O}_{2}(g) \rightarrow 2 \mathrm{Hgo}(a)+2 \mathrm{So}_{2}(g)$

$Mercury Sulphide (II) \quad Oxygen Mercury Oxide (II) \quad Sulphur dioxide$