The measured dipole moment of $\mathrm{ClCH}_{2} \mathrm{CH}_{2} \mathrm{Cl}$ is $1.12 \mathrm{D}$. Which one of the following statements about 1,2 -dichloroethane is false?
(1) It may exist entirely in the anti conformation.
(2) It may exist entirely in the gauche conformation.
(3) It may exist as a mixture of anti and gauche conformations.