Question

A balloon contains 1 L of air at a particular temperature and 75 cm Hg pressure. Keeping the temperature constant if the pressure of air is reduced to 50 cm Hg, then what will be the volume of that air?

• A. 1.5 L
• B. 1.2 L
• C. 1.9 L
• D. 2.1 L

Answer 1

The correct option is A

1.5 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 $P_1=75cmHg:P_2=50cmHg:V_1=1L$

$\Rightarrow V_2=\frac{75\times 1}{50}$

$\Rightarrow V_2=1.5L$

Therefore, the volume of air at 50 cm Hg= 1.5L