Question

A cylinder contained 10 kg of gas at pressure $10^{7}N/m^{2}$. The quantity of gas taken out of cylinder if final pressure is $2.5 \times 10^{6}N/m$is (assume the temperature of gas is constant)

• A. Zero
• B. 7.5 kg
• C. 2.5 kg
• D. 5 kg

Answer 1

Answer: (B)

7.5 kg

Answer 2

At constant temperature for the given volume of gas $\frac{P_{1}}{P_{2}} = \frac{m_{1}}{m_{2}}$

∴ $\frac{10^{7}}{2.5 \times 10^{6}} = \frac{10}{m_{2}}$

⇒ $m_{2} = \frac{2.5 \times 10^{6} \times 10}{10^{7}} = 2.5kg$

∴ The quantity of gas taken out of the cylinder = 10 – 2.5

= 7.5 kg.