Question

Which of the following gas is liberated during extraction of crystalline silicon by reducing silica with coke?

• A. Carbon dioxide
• B. Carbon monoxide
• C. Silicon oxide
• D. Both $A$ and $B$

Answer 1

Answer: (B)

Carbon monoxide

Crystalline silicon is obtained by reducing silica with coke. When excess of silica is heated with coke in the electric furnace in the absence of air dark grey coloured silicon is obtained in its crystalline form.

$Si{O}_2+2C⟶Si+2CO\uparrow$