ICSE Class 10 Chemistry Question 50 of 64

Metallurgy — Question 50

Back to all questions
50
Question

Question 7(2018)

Write a balanced chemical equation for -

(i) The formation of aluminium at the cathode, during the electrolysis of alumina

(ii) Action of heat on aluminium hydroxide.

Answer

(i) At cathode : 2Al3+ + 6e- ⟶ 2Al

(ii) Conversion of Al(OH)3 - to pure alumina - heat on Al(OH)3

2Al(OH)3[aluminium hydroxide]1100°CAl2O3[pure alumina]+3H2O\underset{\text{[aluminium hydroxide]}}{\text{2Al(OH)}_3} \xrightarrow{1100\degree\text{C}} \underset{\text{[pure alumina]}}{\text{Al}_2\text{O}_3} + \text{3H}_2\text{O}