Question

Valency of Carbon in Ch4 , C2H6, C2H4 and C2h2 is how much

Answer 1

Valency of carbon is always 4 and doesn't depend on the compounds it forms.

In $CH_4$, carbon forms 4 single bonds with hydrogen

In $C_2H_6$, each carbon forms 3 single bonds with hydrogen and a single bond between themselves

In $C_2H_4$, each carbon forms 2 single bonds with hydrogen and a double bond between themselves. Hence valency is again 4

In $C_2H_2$ , each carbon forms one single bind with a hydrogen each and a triple bond between themselves. So valency is 4 .

HOPE THIS HELPS!!