Question

A balloon contains $500m^{3}$ of helium at 27⁰C and 1 atmosphere pressure. The volume of the helium at – 3⁰C temperature and 0.5 atmosphere pressure will be

• A. $500m^{3}$
• B. $700m^{3}$
• C. $900m^{3}$
• D. $1000m^{3}$

Answer 1

Answer: (C)

$900m^{3}$

Answer 2

From $PV = \mu RT$ we get $\frac{V_{2}}{V_{1}} = \left( \frac{T_{2}}{T_{1}} \right)\left( \frac{P_{1}}{P_{2}} \right) = \left( \frac{270}{300} \right)\left( \frac{1}{0.5} \right) = \frac{9}{5}$

⇒ $V_{2} = 500 \times \frac{9}{5} = 900m^{3}$