Question

What are the total number of $\sigma$ and $\pi$ bonds in the following molecules?
(a) $C_2{H}_2$
(b) $C_2{H}_4$

Answer 1

(a) Acetylene $C_2{H}_2$ contains $3\sigma$ bonds and $2\pi$ bonds.
(b) Ethylene $C_2{H}_4$ contains $5\sigma$ bonds and $1\pi$ bond.