Question

what is the hybridization of c in the molecule?
part 2 of 2
which structure has a dipole moment?

Explanation:

Step1: Determine hybridization of C

In a molecule with a double - bond, carbon forms three $\sigma$ - bonds and one $\pi$ - bond. The hybridization of carbon in such a case is $sp^{2}$ as one $s$ and two $p$ orbitals hybridize to form three $sp^{2}$ hybrid orbitals for $\sigma$ - bonding.

Step2: Analyze dipole - moment of structures

For the first structure ($\ce{FHC=CFH}$), the bond dipoles do not cancel out due to the non - symmetric arrangement of the polar $\ce{C - F}$ bonds. For the second structure ($\ce{H2C=CF2}$), the bond dipoles of the $\ce{C - F}$ bonds are symmetrically arranged and cancel each other out. So only the first structure has a dipole moment.

Answer:

Part 1: $sp^{2}$
Part 2: The first structure ($\ce{FHC=CFH}$)