Q4 / 155 · WBJEE 2025 · Chemistry
An LPG (Liquified Petroleum Gas) cylinder weighs 15.0 kg when empty. When full, it weighs 30.0 kg and shows a pressure of 3.0 atm . In the course of usage at $27^{\circ} \mathrm{C}$, the mass of the full cylinder is reduced to 24.2 kg . The volume of the used gas in cubic metre at the normal usage condition ( 1 atm and $27^{\circ} \mathrm{C}$ ) is (assume LPG to be normal butane and it behaves ideally)
- A$24.6 \mathrm{~m}^3$
- B$246 \mathrm{~m}^3$
- C$0.246 \mathrm{~m}^3$
- Correct answerD$2.46 \mathrm{~m}^3$
Solution
Weight of gas $=15 \mathrm{~kg}$
Weight of gas in the cylinder after use $=24.2-15.0=9.2$
$\therefore$ Gas used $=15-9.2=5.8 \mathrm{~kg}$
$\begin{aligned}
\therefore V & =\frac{W}{M} \times \frac{R T}{P}=\frac{5.8 \times 10^3 \times 0.0821 \times 300}{58 \times 1} L \\
& =\frac{100 \times .0821 \times 300}{10^3} \mathrm{~m}^3 \\
& =2.463 \mathrm{~m}^3
\end{aligned}$
Hence, the correct answer is option: 'D'.