Question

$2.5\text{L}$ of a sample of a gas at ${27}^{\circ }\text{C}$ and $1\text{bar}$ pressure is compressed to a volume of $500\text{mL}$ keeping the temperature constant. The percentage increase in the pressure is:

• A. 100%
• B. 400%
• C. 500%
• D. 80%

Answer 1

The correct option is B 400%

Given: $P_1=1\text{bar},V_1=2.5\text{L}\text{and}{V}_2=0.5\text{L}$

According to Boyle's Law:
$P_1{V}_1=P_2{V}_2$
$1\times 2.5=P_2\times \frac{1}{2}$
$P_2=5$ bar

$\text{\% Increase in pressure}=\frac{\text{Increase in pressure}}{\text{Initial pressure}}\times 100$
$=\frac{4}{1}\times 100=400\%$