Question

A sample of a gas has a pressure of 1.01atm when the volume is 256mL. What is the pressure of the gas when the volume is 118mL?

Answer 1

Answer : The pressure when the gas occupies a volume of 118 mL is, 2.19 atm.

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 = 1.01 atm

$P_2$ = final pressure of the gas = ?

$V_1$ = initial volume of the gas = 256 mL

$V_2$ = final volume of the gas = 118 mL

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

$1.01atm\times 256mL=P_2\times 118mL$

$P_2=2.19atm$

Therefore, the pressure when the gas occupies a volume of 118 mL is, 2.19 atm.

Answer 2

Answer;

= 2.191 atm

Explanation;

Using the equation ;

P1V1= P2V2 ;

P1 = 1.01 atm, V1= 256 mL

P2 = ? ,  V2 = 118 mL

but;

P2 = P1V1/V2

      = (1.01 × 256)/118

       = 2.191 atm