Question

Which forces oppose the vaporization of each substance?

(a)${\mathbf{Br}}_{\mathbf{2}}$, (b) data-custom-editor="chemistry" ${\mathbf{SbH}}_{\mathbf{3}}$, (c)data-custom-editor="chemistry" ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{NH}}_{\mathbf{2}}$

Short answer

1. ${\mathbf{Br}}_{\mathbf{2}}$: London dispersion forces exist in the molecule. As there is partial electropositive and electronegative exist on each Br-atom. The dispersion force of attraction opposes vaporization.
2. ${\mathbf{SbH}}_{\mathbf{3}}$:The molecule has induced dipole force forming dispersion weak force which opposes the vaporization.
3. ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{NH}}_{\mathbf{2}}$: ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{NH}}_{\mathbf{2}}$molecule shows Hydrogen bonding as the N-atom is more electronegative than H-atom. Hydrogen bond attraction opposes vaporization.

Step-by-step solution

Intermolecular Forces

Intermolecular forces are the interaction which are formed by the attraction of the two having opposite charges(partial positive and partial negative charge). The opposite charge are formed by the presence of the electron-negative atom in the molecule. Due to the presence of an electron-negative atom, there is an induced partial positive charge is generated on the electron-positive charge (or less electron-negative charge) atom. There will be an attraction between the both oppositely charges to form a bond.

Hydrogen bonding: These types of interactions are present in the electropositive and electronegative atom. There are the interaction between the opposite charge atom which are induced by the presence of the electronegative atom.0

Inter-particle interaction Explanation

Theinter-particle interaction is a type of attraction between the atoms in the molecule.

(a)${\mathbf{Br}}_{\mathbf{2}}$:The molecule ${\mathbf{Br}}_{\mathbf{2}}$shows London dispersion bonding. The reason behind this is that Br-atom exists in partial negative and partial positive belongs to halogens group. The weak force opposes the attraction of vaporisation.

(b)${\mathbf{SbH}}_{\mathbf{3}}$:The molecule ${\mathbf{SbH}}_{\mathbf{3}}$ shows weak force shows dispersion bonding. The reason behind this is that Sb-atom forms induced dipole force which opposes the force vaporisation.

(c) ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{NH}}_{\mathbf{2}}$: Hydrogen bond is the bond between the electronegative atom and electropositive atom. The difference in the electronegativity in N-atom and H-atom is large which form a hydrogen bond. The hydrogen bond of attraction opposes the force of vaporization which convert liquid into gaseous.