# How many double covalent bonds are there in a molecule of CO_2?

$\text{Two......}$
The central carbon is $\text{sp-hybridized}$, and the terminal oxygens are $\text{sp"^2-"hybridized}$, i.e. $O = C = O$. And so there are $2 \times C - O$ double bonds....
How many in acetylene, $H - C \equiv C - H$? How many single bonds?