What is the valency of Carbon in C2H2?

Here, carbon has 4 valency......

According to the electronic configuration

C-> 1s²2s²2p², here there are 2 unpaired elctrons, 

but the excitation w1hile bonding (exchange energy)

results in the replacement of e^- (with -1/2 spin) from 2s to 2p (+1/2 spin).

this leaves the carbon atom with 4 unpaired elcetrons which gets paired during 

hybridisation; 

1s²2s¹2p³

Hence it has 4 valency......

@ mudit 
in c2h2 carbon forms 1 triple bond , it shares 3 electron here . 
carbon doesnot gain or loose electron , it only shares the electron . 
so, valency of carbon will be same for every compound as for ethene , ethyle , and ethane . 
HOPE IT CLEARS 
ALL THE BEST ..