Answer
a. dispersion, dipole-dipole forces, and hydrogen bonds.
b. dispersion, dipole-dipole forces, and hydrogen bonds.
c. dispersion forces
d. dispersion forces
Work Step by Step
a. $NCl_{3}$ is a polar molecule, hence it has dispersion, dipole-dipole forces, and hydrogen bonds.
b. $NH_{3}$ is a polar molecule, hence it has dispersion, dipole-dipole forces, and hydrogen bonds.
c. $SiH_{4}$ has a tetrahedral geometry; because of this all the polar forces cancel away so only dispersion forces exist.
d. $CCl_{4}$ has a tetrahedral geometry, and because of this all the polar forces cancel away so only dispersion forces exist.
