Question

A cylinder contains 18 moles of oxygen at pressure of 15 atmosphere at temperature 300 K. If the pressure reduces to 9 atmospheres by the withdrawal of 6 moles of oxygen, then the temperature of the cylinder will be reduced to

• A. 200 K
• B. 230 K
• C. 270 K
• D. 220 K
• E. 250 K

Hint:

Logic Tip: By observing ratios, you can solve this mentally. The pressure ratio $P_2/P_1$ is $9/15 = 3/5$. The mole ratio $n_2/n_1$ is $12/18 = 2/3$. Since $T \propto P/n$, the new temperature is $T_2 = T_1 \times \frac{3/5}{2/3} = 300 \times \frac{9}{10} = 270\text{ K}$.

Answer 1

The Correct Option is C