Question

Chlorine is more easily liquefied than ethane because ("a” and "b" are van der waals constants for gases), a for $C{l}_2$ is a for $C_2{H}_6$ but b for $C{l}_2$ is a for $C_2{H}_6$

• A. greater than
• B. lesser than
• C. equal to
• D. equal to

Answer 1

Answer: (A), (B)

lesser than

$C{l}_2$ is more easily liquefied.

⇒ “ a” for $C{l}_2$ > “a” for $C_2{H}_6$.

This is obvious from theory of compressibility. Greater means more appreciable attractive forces. This initially adds compression and thus liquefaction. Since liquefaction of $C{l}_2$ is easier.

$\Rightarrow$compression at higher pressure are not impeded. The tendency to repel (between individual atoms) at high pressure is lower.

$\Rightarrow$ Excluded volume is lesser for $C{l}_2$ than $C_2{H}_6$. So,” a” for $C{l}_2$ >” a” for $C_2{H}_6$ and “ b” for $C{l}_2$ < “b” for $C_2{H}_6$ .

In other words, Liquefaction $\propto \frac{a}{b}$.