Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
The van der Waals' equation for $0.5 \mathrm{~mol}$ of a gas is
ChemistryStates of MatterTS EAMCETTS EAMCET 2019 (04 May Shift 2)
Options:
  • A $\left(p+\frac{a}{4 V^2}\right)\left(\frac{V-b}{2}\right)=R T$
  • B $\left(p+\frac{a}{4 V^2}\right)(2 V-b)=R T$
  • C $\left(p+\frac{a}{4 V^2}\right)(2 V-4 b)=R T$
  • D $\left(p+\frac{a}{4 V^2}\right)=\frac{2 R T}{2(V-b)}$
Solution:
2780 Upvotes Verified Answer
The correct answer is: $\left(p+\frac{a}{4 V^2}\right)(2 V-b)=R T$
van der Waals' equation is
$$
\left(p+\frac{a n^2}{V^2}\right)(V-n b)=n R T
$$
where, $\quad a=$ correction in pressure
$b=$ correction in volume
$n=$ number of moles

Given, $\quad n=0.5 \mathrm{~mol}$
$$
\left(p+\frac{a(0.5)^2}{V^2}\right)(V-0.5 b)=0.5 R T
$$
or $\quad\left(p+\frac{a}{4 V^2}\right)(2 V-b)=R T$
Thus, option (2) is correct.

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.