Question

A vessel contains 1.5L of gas at a particular temperature and 60 cm Hg pressure. Keeping the temperature constant if the pressure of air is increased to 80 cm Hg, then what will be the volume of that gas?

• A. 2.125 L
• B. 1.125 L
• C. 1.5 L
• D. 1.75 L

Answer 1

The correct option is B

1.125 L

As the temperature is constant, here Boyle's law is applied,

According to Boyle's law: $P_1{V}_1=P_2{V}_2\Rightarrow V_2=\frac{P_1{V}_1}{P_2}$

Here $P_1=60cmHg:P_2=80cmHg{V}_1=1.5L$

$\Rightarrow V_2=\frac{60\times 1.5}{80}$

$\Rightarrow V_2=1.125L$

Therefore, the volume of air at 80 cm Hg= 1.125L