Question

Under a pressure of 3000N/m2, a gas has a volume of 250cm3. What will be its volume if the pressure is changed to 100mmHg at the same temperature?

[ 760mmHg = 101325N/m2]

Answer 1

This task is based on Boyle's Law: $PV=const$

So $P_1V_1=P_2V_2$ , P₁ and P₂ - initial and final pressure of a gas respectively, V₁ and V₂ - initial and final volume of a gas respectively.

Express V₂: $P_1V_1/P_2=V_2$

Pressure must be converted to the same units, use proportion:

760mmHg=101325N/m²

100mmHg=x (P₂)

$x=100mmHg*101325N/m^2/760mmHg=13332N/m^2$

V₂=3000N/m²*250cm³/13332N/m²=56,3cm³

Answer: 56,3cm³.