Question

$H-C-H$ bond angle in ethene and ethane are ________ respectively.

• A. ${120}^0$ and ${109.5}^0$
• B. ${180}^0$ and ${109.5}^0$
• C. ${109.5}^0$ and ${120}^0$
• D. ${120}^0$ and ${180}^0$

Answer 1

The correct option is A ${120}^0$ and ${109.5}^0$

In ethene, carbon shows $s{p}^2$ hybridization and shows trigonal geometry with carbon is at the center and the hydrogen atom at the three corners of the triangle. Thus it shows H-C-H bond angle of ${120}^0$.

In ethane, carbon shows $s{p}^3$ hybridization and shows tetrahedral geometry with carbon is at the center and hydrogen atom at four corners of a regular tetrahedron. Thus it shows a bond angle of ${109.5}^0$

Hence, the correct option is $\text{A}$