What is the Observed H-C-C Bond Angle in Ethylene

Question

What is the observed H-C-C bond angle in ethylene?
A) 180°
B) 90°
C) 109.5°
D) 121.7°

Accepted Answer

The observed H-C-C bond angle in ethylene is 121.7°. This is because the carbon atoms in the molecule have trigonal planar electron geometry and the hydrogens attached to them are repelling each other, causing the bond angle to deviate from the ideal tetrahedral angle of 109.5°. The actual bond angle is closer to the value of 120°, which is the optimal angle to minimize repulsion between the hydrogens.