Question

Which substance has the higher boiling point? Explain.

(a) ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{CH}}_{\mathbf{2}}\mathbf{OH}$or ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{CH}}_{\mathbf{2}}{\mathbf{CH}}_{\mathbf{3}}\mathbf{}\mathbf{}$(b) NO or data-custom-editor="chemistry" ${\mathbf{N}}_{\mathbf{2}}$ (c) ${\mathbf{H}}_{\mathbf{2}}\mathbf{S}$ or_{${\mathbf{H}}_{\mathbf{2}}\mathbf{Te}$}

Short answer

1. ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{CH}}_{\mathbf{2}}\mathbf{OH}$or ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{CH}}_{\mathbf{2}}{\mathbf{CH}}_{\mathbf{3}}\mathbf{}\mathbf{}$: ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{CH}}_{\mathbf{2}}\mathbf{OH}$molecule has a higher boiling point than ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{CH}}_{\mathbf{2}}{\mathbf{CH}}_{\mathbf{3}}\mathbf{}\mathbf{}$.
2. NOor ${\mathbf{N}}_{\mathbf{2}}$:NO has a higher boiling point than${\mathbf{N}}_{\mathbf{2}}$ .
3. ${\mathbf{H}}_{\mathbf{2}}\mathbf{S}$or ${\mathbf{H}}_{\mathbf{2}}\mathbf{Te}$:${\mathbf{H}}_{\mathbf{2}}\mathbf{S}$molecule shows higher boiling point than ${\mathbf{H}}_{\mathbf{2}}\mathbf{Te}$ .

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 and 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 oppositely charged atom which are induced by the presence of the electronegative atom.

Ion-dipole interaction: These interactions are present in the ion and polar molecules. These interactions are similar to the dipole-dipole interaction.

Inter-particle interaction Explanation  

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

(a)${\mathbf{CH}}_{\mathbf{3}}{\mathbf{CH}}_{\mathbf{2}}\mathbf{OH}$or${\mathbf{CH}}_{\mathbf{3}}{\mathbf{CH}}_{\mathbf{2}}{\mathbf{CH}}_{\mathbf{3}}\mathbf{}\mathbf{}$ :The molecule shows hydrogen bonding between O-atom and H-atom and the bonding between is induced dipole interaction which is called London dispersion force. Now, the hydrogen bond is stronger than the dispersion force, hence, the boiling point is higher in ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{CH}}_{\mathbf{2}}\mathbf{OH}$.

(b) NOordata-custom-editor="chemistry" ${\mathbf{N}}_{\mathbf{2}}$ :The data-custom-editor="chemistry" ${\mathbf{N}}_{\mathbf{2}}$is a non-polar molecule which shows London dispersion force and the bonding between the NO is ion-dipole force. The ion-dipole force is a more strong force of attraction than the London dispersion force. That is why the boiling point is higher in NO.

(c)data-custom-editor="chemistry" ${\mathbf{H}}_{\mathbf{2}}\mathbf{S}$ordata-custom-editor="chemistry" ${\mathbf{H}}_{\mathbf{2}}\mathbf{Te}$ : Both molecules has hydrogen bonding which is between the electronegative atom and electropositive atom. The hydrogen bond is strong indata-custom-editor="chemistry" ${\mathbf{H}}_{\mathbf{2}}\mathbf{S}$ molecules than data-custom-editor="chemistry" ${\mathbf{H}}_{\mathbf{2}}\mathbf{Te}$. Therefore, the boiling point is higher in data-custom-editor="chemistry" ${\mathbf{H}}_{\mathbf{2}}\mathbf{S}$.