Identify the compounds that will have a net (nonzero) dipole moment. Justify your answer and show the direction of each.
(i) AsCl₅
(ii) Fluoromethane, CH₃F
(iii) SeCl₆
(iv) SF₂

• A. (i) AsCl₅ has a net dipole moment. Cl is more electronegative than As and because it has a trigonal bipyramidal geometry, the dipole moments are not canceled out.
  (iii) SeCl₆ has a net dipole moment. Cl is more electronegative than Se and because it has an octahedral geometry, the dipole moments are not canceled out.
• B. (i) AsCl₅ has a net dipole moment. Cl is more electronegative than As and because it has a trigonal bipyramidal geometry, the dipole moments are not canceled out.
  (ii) Fluoromethane, CH₃F has a net dipole moment. F is more electronegative than C and H and because it has a tetrahedral geometry, the dipole moment is not canceled out.
• C. (ii) Fluoromethane, CH₃F has a net dipole moment. F is more electronegative than C and H and because it has a tetrahedral geometry, the dipole moments are not canceled out.
  (iv) SF₂ has a net dipole moment. F is more electronegative than C and H and because it has a tetrahedral geometry, the dipole moments are not canceled out.
• D. (ii) Fluoromethane, CH₃F has a net dipole moment. F is more electronegative than C and H and because it has a tetrahedral geometry, the dipole moment is not canceled out.
  (iii) SeCl₆ has a net dipole moment. Cl is more electronegative than Se and because it has an octahedral geometry, the dipole moments are not canceled out.

Answer: (C)