Question #33c98

1 Answer
Oct 3, 2015

See explanation.

Explanation:

The structures of #CF_4# and #CHF_3# are:
enter image source here
Here is how we draw the dipole moments:
enter image source here

Rules to draw dipole moments:

  1. The arrow direction is from the less electronegative element to the the more electronegative element, which depicts the direction on which the electrons are being pulled.
  2. Since we consider that carbon and hydrogen have similar electronegativity, there is no dipole moment between them or you could draw a very small arrow from hydrogen to carbon.

#CF_4# is a non-polar molecule because all dipole moments cancel out since it has a tetrahedral geometry, however, #CHF_3# is a polar molecule since the dipole moments do not cancel out.