Question

Predict the chemical formula of butyne, having one carbon-carbon triple bond.

Answer 1

Triple bonds usually have a general formula of \[C _{2}H _{2n-2}\]
So if you have butyne, you have 4 carbons. Do the math. :)

Answer 2

I mean alkynes not triple bonds. Sorry, it was kinda vague.

Answer 3

if you have an alkyne with only one triple bond, as @kem08 suggests, then the general formula is always the same