Intermolecular Forces and Thermal Energy

Identify a pair of molecules which shows dipole-induced dipole forces.

Explain briefly the dipole-induced dipole forces among the particles?

There are two types of hydrogen bonding.

Which of the following show intramolecular hydrogen bonding?

Which of these does not show hydrogen bonding?

What is hydrogen bolding?

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.

Match the type of interaction in column $\mathrm{A}$ with the distance dependence of their interaction energy in column $\mathrm{B}:$

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?

Use the information and data given below to answer the questions (a) to (c):

• Stronger intermolecular forces result in higher boiling point.

• Strength of London forces increases with the number of electrons in the molecule.

• Boiling point of $\mathrm{HF}, \mathrm{HCl}, \mathrm{HBr}$ and $\mathrm{HI}$ are $293 \mathrm{K}, 189 \mathrm{K}, 206 \mathrm{K}$ and $238 \mathrm{K}$ respectively.

(b) Looking at the trend of boiling points of $\mathrm{HCl}, \mathrm{HBr}$ and $\mathrm{HI}$, explain out of dipole-dipole interaction and London interaction, which one is predominant here.
 

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.