Question

what is the valency of carbon in CCI4 and CO2​

Answer 1

$\sf \red{The} \: \: \bf \green {Required} \: \: \tt \blue{Answer} \: \: \mathfrak \pink{is}\orange{:}$

Valency of Carbon in CCl4 is +4. Because the valency of Cl is -1 and to nutralize (-1×4) = -4, the carbon atom is needed to be in +4 state.