Question

Rank the species CH2NH, CH3I, HF, C2H6 from most to least miscible in ammonia (NH3) 1. CH3I > C2H6 > HF > CH2NH 2. CH2NH > HF > C2H6 > CH3I 3. HF > CH3I > C2H6 > CH2NH 4. HF > CH2NH > CH3I > C2H6 5. CH2NH > HF > CH3I > C2H6

Answer 1

Answer:

$HF>CH_{2}NH>CH_{3}I>C_{2}H_{6}$

Explanation:

$NH_{3}$ is an weak base. HF is an weak acid. Hence an acid-base reaction will ocuur between $NH_{3}$ and HF resulting a homogeneous mixture.

$NH_{3}$ is a polar protic molecule. Hence it can form hydrogen bonding with another polar protic molecule $CH_{2}NH$. Also dipole-dipole attraction force along with london dispersion force exists between $CH_{2}NH$ and $NH_{3}$.

$CH_{3}I$ is a polar molecule. Hence only dipole-dipole attraction force along with london dispersion force operates between $CH_{3}I$ and $NH_{3}$.

$C_{2}H_{6}$ is a non-polar molecule. Hence only london dispersion force exists between $C_{2}H_{6}$ and $NH_{3}$.

So, order of miscibility: $HF>CH_{2}NH>CH_{3}I>C_{2}H_{6}$

                                   (most)                                (least)