Answer
The Group IV hydrides have the weakest intermolecular interactions in each period. These are the only hydrides that have no dipole moment. Thus, the boiling point of the hydrides increases with increasing molecular weight. Larger and heavier molecules have stronger Vander waals forces. Again, boiling points increase as the forces of attraction between molecules increase.Thus, boiling points increase from $CH_{4}$ to $SnH_{4}$.
Work Step by Step
The Group IV hydrides have the weakest intermolecular interactions in each period. These are the only hydrides that have no dipole moment. Thus, the boiling point of the hydrides increases with increasing molecular weight. Larger and heavier molecules have stronger Vander waals forces. Again, boiling points increase as the forces of attraction between molecules increase.Thus, boiling points increase from $CH_{4}$ to $SnH_{4}$.