Question

$a$ and $b$ are van der Waals' constants for gases. Chlorine is more easily liquefied than ethane because

• A. Value of $a\text{for}C{l}_2>C_2{H}_6$
  Value of $b\text{for}C{l}_2<C_2{H}_6$
• B. Value of $a\text{for}C{l}_2<C_2{H}_6$
  Value of $b\text{for}C{l}_2<C_2{H}_6$
• C. Value of $a\text{for}C{l}_2>C_2{H}_6$
  Value of $b\text{for}C{l}_2>C_2{H}_6$
• D. Value of $a\text{for}C{l}_2<C_2{H}_6$
  Value of $b\text{for}C{l}_2>C_2{H}_6$

Answer 1

The correct option is A Value of $a\text{for}C{l}_2>C_2{H}_6$

Value of $b\text{for}C{l}_2<C_2{H}_6$
If gas is more easily liquefied then attractive forces are larger i.e higher value of 'a' and lower value of 'b' which is measure of molecular size.
Thus, $a\left(C{l}_2\right)>a\left(C_2{H}_6\right)$
$b\left(C{l}_2\right)<b\left(C_2{H}_6\right)$
Therefore, Chlorine is more easily liquified than ethane.