Question

An ideal gas at 1 bar is heated from 273 K to 373 K at constant pressure. If its initial volume is 5.46 L, what will be the final volume?

• A. 7.46 L
• B. 1.865 L
• C. 5.46 L
• D. 6 L

Answer 1

The correct option is A 7.46 L

This question deals with changes in volume of a gas with change in temperature, with pressure remaining constant.

This is dealt by Charles's law which states that pressure remaining constant, volume of a gas is directly proportional to its temperature.

i.e $V$ α $T$ or $\frac{V}{T}=k$, where $k$ is a constant.

Thus, $\frac{V_1}{T_1}=\frac{V_2}{T_2}$, where $V_1$ and $T_1$ refer to the initial volume and temperature respectively where as $V_2$ and $T_2$ refer to the final volume and temperature respectively.

$\frac{V_1}{T_1}=\frac{V_2}{T_2}$

$\Rightarrow V_2=\frac{V_1\times T_2}{T_1}=\frac{5.46\times 373}{273}$

$\Rightarrow V_2=7.46L$