Question

If the dipole moment of CH₃F is 1.847 D and the dipole moment of CD₃F is 1.858 D, which is more electronegative: hydrogen or deuterium?

Short answer

Hydrogen is more electronegative than deuterium.

Step-by-step solution

Defining dipole moment and electronegativity

Electronegativity is the tendency of an atom to pull a shared pair of electrons towards itself.

Dipole moment is product of separation between two opposite charges and the charge itself.

finding out the more electronegative atom

Individual bond dipoles affect the overall dipole moment of a molecule.

CH₃ is 1.847 D which is less compared to the other molecule as the difference between the dipole moment of C-F bond and the combined dipole moment of three C-H bonds is less.

Thus we can conclude that the pull of three C-H bonds with respect to C-F bond is greater than the pull of three C-D bonds. As a result hydrogen can be concluded to be more electronegative compared to deuterium