Question

which one of the molecules shown below has no net molecular dipole moment? ch₃cl ch₂cl₂ h₂cch₂ ch₂o ch₃oh

Explanation:

A molecule has no net dipole moment if its molecular geometry is symmetrical, canceling out bond dipoles. \( \text{H}_2\text{C}=\text{CH}_2 \) (ethene) is planar and symmetrical (trigonal planar around each C, overall planar with symmetric electron distribution), so bond dipoles (C - H) cancel. Other options (\( \text{CH}_3\text{Cl} \), \( \text{CH}_2\text{Cl}_2 \), \( \text{CH}_2\text{O} \), \( \text{CH}_3\text{OH} \)) have asymmetric structures, leading to net dipole moments.

Answer:

\( \boldsymbol{\text{H}_2\text{CCH}_2} \) (or \( \boldsymbol{\text{H}_2\text{C}=\text{CH}_2} \), ethene)