Given van der Waals' constant for `NH_3, H_2, O_2 " and " CO_2 " are respectively " 4.17, 0.244, 1.36 " and " 3.59`, which one of the following gases is most easily liquefied?

Options

A. `O_(2)`
B. `H_(2)`
C. `NH_(3)`
D. `CO_(2)`

Answer

C

Explanation

In the van der Waals' equation,
`[P+(an^(2))/(V^(2))](V-nb)=nRT`
'a' and 'b' are known as van der Waals' constant. 'a' is the measure of force of attraction between gas molecules. Greater the value of a, easier the liquefaction of the gas.
Thus, among `NH_(3)(4.17), H_(2)(0.244),O_(2)(1.36)` and `CO_(2)(3.59)`, the value of a is greatest in `NH_(3)`, hence it is most easily liquefied.