Question

A container holds a sample of hydrogen gas at 300 K. The temperature decreased to 100 K and the pressure remained constant, and the volume changed to 1.0 L. What was the original volume?

Answer 1

Answer : The original volume of gas was, 3.0 L

Explanation :

Charles' Law : It is defined as the volume is directly proportional to the temperature of the gas at constant pressure and number of moles.

$V\propto T$

or,

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

where,

$V_1\text{ and }T_1$ are the initial volume and temperature of the gas.

$V_2\text{ and }T_2$ are the final volume and temperature of the gas.

We are given:

$V_1=?\\T_1=300K\\V_2=1.0L\\T_2=100K$

Now put all the given values in above equation, we get:

$\frac{V_1}{300K}=\frac{1.0L}{100K}\\\\V_1=3.0L$

Thus, the original volume of gas was, 3.0 L