Question

If one mole of a gas originally at STP is placed in a container where the pressure is doubled and the temperature in K is tripled, what is the new volume in the liter?

• A. 2.2
• B. 5.6
• C. 7.5
• D. 11.2
• E. 33.6

Answer 1

Answer: (E)

33.6

Option E is the correct answer.

One mole of any gas at STP occupies 22.4 L of volume. Ideal gas equation can be written as $PV$ = $nRT$

where $V$ = $\frac{nRT}{P}$

Thus $22.4$ = $\frac{RT}{P}$, because n equals to 1

When the pressure is doubled and temperature is trippled the new equation now becomes $V$ = $\frac{3RT}{2P}$

That is, the new volume becomes $\frac{3}{2}$ times the original volume. Original volume was 22.4 L.

Thus the new volume is $\frac{3}{2}$ $\ast$ $\frac{RT}{P}$

Which is $\frac{3}{2}$ $\ast$ $22.4$ which is equal to 33.6 Litres.