Question

Arrange the following in increasing order of their intermolecular forces : Nylon-$66(I)$, Buna-$S(II)$, Polythene $(III)$

• A. II, I, III
• B. III, II, I
• C. I, II, III
• D. II, III, I

Answer 1

Answer: (D)

Nylon-$66$ is a fibre and has hydrogen bonding as intermolecular force. Buna-$S$ is an elastomer and has weak van der Waals' forces. Polythene is thermoplastic and has intermediate intermolecular forces (ie, stronger than elastomer but weaker than fibre).
Thus, the order of intermolecular forces is
$\underset{(II)}{\text{Buna-S}}<\underset{(III)}{\mathrm{polythene}}<\underset{(I)}{\text{Nylon}-66}$