Question

500.0 liters of a gas are prepared at 700.0 mmHg and 200.0 C. The gas is placed into a tank under high pressure. When the tank cools to 20.0 C, the pressure of the gas is 30.0 atm. What is the volume of the gas?

Answer 1

The key to answering this question is to know that `1*atm` pressure will support a column of mercury that is `760*mm` high...I gets a final volume of approx. `10*L`.

Explanation:

And thus `760*mm*Hg-=1*atm`

The combined gas equation tells us that `(P_1V_1)/T_1=(P_2V_2)/T_2` given a constant molar quantity of gas.

So we solve for `V_2`, where `V_2` is conceived to be the volume of the tank.....

`V_2=(P_1V_1)/T_1xxT_2/P_2`, and we immediately see (do we?) that we gots units of volume.........

`V_2=((700*mm*Hg)/(760*mm*Hg*atm)xx500*L)/(473.15*K)xx(293.15*K)/(30*atm)~=10*L`