Question

A balloon contains $500m^3$ of He at ${27}^o$C and $1$ atmospheric pressure. The volume of He at $-3^o$C and $0.5$ atmospheric pressure will be.

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

Answer 1

The correct option is B $900m^3$

Using standard gas equation,
$\frac{p_1{V}_1}{T_1}=\frac{p_2{V}_2}{T_2}$ or $V_2=\frac{p_1{V}_1{T}_2}{p_2{T}_1}$
$\therefore V_2=\frac{1\times 500\times (273-3)}{0.5\times (273+27)}$
$V_2=\frac{1\times 500\times 270}{0.5\times 300}$
$V_2=900m^3$.