Question

What is the $S.I$. unit of van der Waals’ constant ${}^{\prime }{a}^{\prime }$ ?

• A. $PaL$ mol${}^{-2}$
• B. $Pa{m}^3$mol${}^{-2}$
• C. $Pa{m}^{6}mo{l}^{-2}$
• D. $Pa{m}^{6}mo{l}^{-1}$

Answer 1

Answer: (C)

As we know, $P=\frac{a{n}^2}{V^2}$
$a=\frac{P{V}^2}{n^2}$
$=\frac{\left(Pa\right){\left(m^3\right)}^2}{{\left(mol\right)}^2}$
$=Pa{m}^6$ mol ${}^{-2}$