Intermolecular Forces and Thermal Energy

The intermolecular attraction that is dependent on the inverse cube of the distance between the molecules is _____(London force/Hydrogen bond)

Define thermal energy of a substance.

Gases do not settle at the bottom of a container. Why?

Arrange solid, liquid and gas in order of increasing thermal energy, giving reasons.

The increasing order of viscosity of the following compounds is given as 

hexane < ${\mathrm{H}}_2\mathrm{O}$ < glycerol

Which of the following is the correct reason?

Gases expand and occupy all the space available to them. Which of the following assumption explain this behaviour correctly?

Gases show _____ (high/ low) diffusion as compared to solid and liquid.

The intermolecular attraction that is dependent on the inverse cube of the distance between the molecules is

Assertion. ${\mathrm{H}}_2\mathrm{O}$ is the only hydride of group-16 which is liquid at ordinary temperature.

Reason. In ice, each oxygen atom is surrounded by two covalent bonds and two hydrogen bonds.

Assertion. Both o-hydroxy benzaldehyde and p-hydroxy benzaldehyde have same molecular weight and show H-bonding.

Reason. Melting point of p-hydroxy benzaldehyde is more.

Assertion. The ${\mathrm{HF}}_2^{-}$ ion exists in the solid-state and also in the liquid state but not in an aqueous solution.

Reason. The magnitude of hydrogen bonds in between $\mathrm{HF}-\mathrm{HF}$  molecules are weaker than that in between $\mathrm{HF}$ and ${\mathrm{H}}_2\mathrm{O}$ molecules.

Statement-I. The boiling point of ${\mathrm{NH}}_3$ lies between that of ${\mathrm{SbH}}_3$ and ${\mathrm{BiH}}_3$ .

Statement-2. ${\mathrm{PH}}_3$ has much lower boiling point than ${\mathrm{NH}}_3$ but it increases from ${\mathrm{PH}}_3$ to ${\mathrm{AsH}}_3$ to ${\mathrm{SbH}}_3$ to ${\mathrm{BiH}}_3$ due to increase in van der Waals forces.

Statement-I. o-Nitrophenol has a higher boiling point than p-Nitrophenol.

Statement-2. Intramolecular hydrogen bonding occurs in o-Nitro-phenol.

When two ice cubes are pressed over each other, they unite to form one cube which of the following force is responsible to hold them together?

Intermolecular forces in liquid are

The enthalpy of vaporization of ${\mathrm{H}}_2\mathrm{O}, {\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}, \mathrm{and} {\mathrm{CS}}_2 \mathrm{are} 40.6, 38.6, \mathrm{and} 26.8 \mathrm{kJ} {\mathrm{mol}}^{-1}$ respectively. The order of decreasing intermolecular forces in these liquids is,

The intermolecular force of attraction is very feeble in gases. 

Define the following terms:
Intermolecular forces.

In liquids, the forces of attraction between molecules are _____  than in solids.

The intermolecular force of attraction is the weakest in _____ state of matter. (Gaseous/Liquid)