Question

A cylinder is filled with 10.0L of gas and a piston is put into it. The initial pressure of the gas is measured to be 209.kPa. The piston is now pulled up, expanding the gas, until the gas has a final volume of 78.0L. Calculate the final pressure of the gas. Be sure your answer has the correct number of significant digits.

Answer 1

Answer : The final pressure of the gas will be, 26.8 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 = 209 kPa

$P_2$ = final pressure of the gas = ?

$V_1$ = initial volume of the gas = 10.0 L

$V_2$ = final volume of the gas = 78.0 L

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

$209kPa\times 10.0L=P_2\times 78.0L$

$P_2=26.8kPa$

Therefore, the final pressure of the gas will be, 26.8 kPa