Question

The structures to two compound `(I)` and `(II)` are given below. Which statement is correct ?
`F_(2)C=C=CF_(2)(I)` and `F_(2)C=C=C=CF_(2)(II)`
A. Compound `(I)` shows dipole moment but `(II)` does not.
B. Compound `(II)` shows dipole moment but `(I)` does not.
C. Both show dipole moment.
D. Neither of them shows moment.

Answer 1

Correct Answer - a
a.
They are not in one plane because `C_(2)` is sp - hybridised and is linear, whereas `C_(1)` and `C_(3)` are s`p_(2)-` hybridised.
So they will show dipole moment.
But
They are in one plane and will not show dipole moment.
Rule `:` Even number of double bonds with all same four groups wil show dipole moment and odd number of double bonds with same four groups will not show dipole moment.