Question

Question 10 (1 point) Which intermolecular force increases with increasing molar mass? OX-forces O dispersion forces O dipole-dipole forces hydrogen bonding O none of the above

Answer 1

Answer:

The correct answer is dispersion forces.

Reason: Dispersion forces are intermolecular forces that are dependent on contact between the molecules. This means more the surface area(more contact) of the molecules, more will the forces. And as the molar mass increases ( bigger molecules), the surface area also increases thereby increasing the strength of dispersion forces.

Why other options are wrong?

X-forces: Not appliable. Not under intermolecular forces.

Dipole dipole forces: forces depend on the polarity of the molecules. They increase with increasing polarity and are not completely dependent on Molar Masses.

Hydrogen bond: This is the bond between hydrogen and an electronegative atom like N,O and F.

This is another type of dipole dipole forces which largely depend upon electronegativities of the atom and the dipole moment between them.

Hence increasing molar masses do increase them