Question

The values of van der Waals constant $a$ for $O_2,N_2,N{H}_3$ and $C{H}_4$ are $1.360,1.390,4.170$ and $2.253$ dm${}^6$ atm mol${}^{-2}$ respectively. The gas which can be most easily liquefied is:

• A. $O_2$
• B. $N_2$
• C. $N{H}_3$
• D. $C{H}_4$

Answer 1

Answer: (C)

$N{H}_3$

Easily liquefiable gases have larger ${}^{\prime }{a}^{\prime }$ value. ${}^{\prime }{a}^{\prime }$ is the measure of intermolecular attraction between gaseous molecules.

Since, $N{H}_3$ has a larger ${}^{\prime }{a}^{\prime }$ value, it can be liquefied most easily.

Hence, the correct answer is option $\text{C}$.