Question

NF₃ is less polar than NH₃ because ______.

Options

• F is more reactive than H.

• NH₃ forms associated molecules.

• The resultant of bond polarity is less.

• The resultant of the individual polarities is opposed by the polarity of lone pair.

Answer 1

NF₃ is less polar than NH₃ because the resultant of the individual polarities is opposed by the polarity of lone pair.

Explanation:

NF₃ is less polar than NH₃ because in NF₃, the bond dipoles due to \[\ce{N - F}\] bonds point away from nitrogen, and the lone pair polarity on nitrogen opposes these bond dipoles, reducing the overall molecular polarity. In contrast, in NH₃, the bond dipoles and lone pair polarity reinforce each other, making NH₃ more polar. Thus, the resultant dipole moment in NF₃ is less due to this opposition of bond and lone pair polarities.