Draw a three-dimensional representation for each molecule. Indicate which ones have a dipole moment and in what direction it is pointing. (a) \(\mathrm{CH}_{3} \mathrm{~F}\) (b) \(\mathrm{CH}_{2} \mathrm{Cl}_{2}\) (c) \(\mathrm{CH}_{2} \mathrm{ClBr}\) (d) \(\mathrm{CFCl}_{3}\) (e) \(\mathrm{CCl}_{4}\) (f) \(\mathrm{CH}_{2}=\mathrm{CCl}_{2}\) (g) \(\mathrm{CH}_{2}=\mathrm{CHCl}\) (h) \(\mathrm{HC} \equiv \mathrm{C}-\mathrm{C} \equiv \mathrm{CH}\) (i) \(\mathrm{CH}_{3} \mathrm{C} \equiv \mathrm{N}\) (j) \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{C}=\mathrm{O}\) (k) \(\mathrm{BrCH}=\mathrm{CHBr}\) (two answers)

Question: Based on the analysis provided, identify which molecules have a net dipole moment and the direction of the dipole moment in each case. Answer: The molecules with a net dipole moment and their directions are: (a) CH3F: Dipole moment towards the fluorine atom (c) CH2ClBr: Dipole moment due to the difference in electronegativity between Cl and Br atoms (d) CFCl3: Dipole moment towards the fluorine atom (f) CH2=CCl2: Dipole moment towards the chlorine atoms (g) CH2=CHCl: Dipole moment towards the chlorine atom (i) CH3C≡N: Dipole moment towards the nitrogen atom (j) (CH3)2C=O: Dipole moment towards the oxygen atom (k) BrCH=CHBr (cis-isomer): Dipole moment in the direction angled between the Br atoms.