Question

which statement best helps to explain the observation that nh₃(l) boils at -28°c, whereas ph₃(l) boils at -126°c? a the dispersion forces in nh₃ are weaker than the dispersion forces in ph₃. b the dispersion forces in nh₃ are stronger than the dipole - dipole forces in ph₃. c nh₃ has hydrogen bonding that is stronger than the dipole - dipole forces in ph₃. d nh₃ has hydrogen bonding that is weaker than the dipole - dipole forces in ph₃.

Explanation:

Hydrogen bonding is a stronger intermolecular force than dipole - dipole forces. $NH_3$ has hydrogen bonding due to the N - H bonds, while $PH_3$ has only dipole - dipole forces. Stronger intermolecular forces lead to higher boiling points.

Answer:

C. $NH_3$ has hydrogen bonding that is stronger than the dipole - dipole forces in $PH_3$