Give the general formula of ''alkynes''. Identify the alkynes from the following:
`CH_(4),C_(2)H_(6),C_(2)H_(2),C_(3)H_(4),C_(2)H_(4)`

Explanation

The general formula of alkynes is `C_nH_(2n-2)` where `n` is the number of carbon atoms in one molecule of the alkyne . Out of the above given hydrocarbons `C_(2)H_(2) and C_(3)H_(4)` are alkynes because they correspond to the general formula `C_(n)H_(2n-2)` with `n=2` and `n=3`, respectively. Please note that in an alkyne molecule, the number of hydrogen atoms is `2` less than double the number of carbon atoms.