A given mass of oxygen occupies 200 ml when the pressure is 400 mm of Hg. What volume will the gas occupy when the pressure is raised to 200 mmHg, provided the temperature remains constant?

1 Answer
Apr 18, 2017

At constant temperature, P_1V_1=P_2V_2P1V1=P2V2........V_2=400*mLV2=400mL

Explanation:

Now we know that 1*atm1atm pressure will support of column of mercury 760*mm760mm high. A pressure of LESS than one atmosphere will support a column of mercury LESS than this length.

So here P_1=(400*mm)/(760*mm*Hg*atm^-1)=0.526*atmP1=400mm760mmHgatm1=0.526atm

And P_2=(200*mm)/(760*mm*Hg*atm^-1)=0.263*atmP2=200mm760mmHgatm1=0.263atm

So P_2P2 was half of P_1P1.

And we plug in the numbers, and expect reasonably that V_2V2 WILL INCREASE, given that we reduce the pressure, the force per unit area on the gas:

V_2=(0.526*atmxx200*mL)/(0.263*atm)=400*mLV2=0.526atm×200mL0.263atm=400mL