Question

A fixed mass of a gas at 293K and 100kPa pressure has a volume of 450 cm3. At what pressure the volume of the gas becomes 2000 cm3, at the same temperature?

Answer 1

Answer : The final pressure is, 2.25 kPa

Explanation :

According to the Boyle's law, the pressure of the gas is inversely proportional to the volume of the gas at constant temperature of the gas and the number of moles of gas.

$P\propto \frac{1}{V}$

or,

$PV=k$

or,

$P_1V_1=P_2V_2$

where,

$P_1$ = initial pressure of the gas = 100 kPa

$P_2$ = final pressure of the gas = ?

$V_1$ = initial volume of the gas = $450cm^3$

$V_2$ = final volume of the gas = $2000cm^3$

Now put all the given values in this formula, we get the final pressure of the gas.

$100kPa\times 450cm^3=P_2\times 2000cm^3$

$P_2=2.25kPa$

Therefore, the final pressure is, 2.25 kPa