Question

H2 stored in a 50.0 L container has a pressure of 500.0 torr. O2 stored in a 25.0 L container has a pressure of 800.0 torr. If both these gases are released together to be stored in a 100.0 L container, what is the total pressure in the 100.0 L container?

Answer 1

There is a short way and a long way to do this. Here is the long way.
Use PV = nRT and solve for n = mols H2 gas in the 50.0L container. You don't have a T listed so make up one and use it throughout the problem.
Use PV = nRT and solve for n = mols O2 in the 25.0 L container. Add nH2 + nO2 = total mols and use PV = nRT and solve for P in the 100.0 L container. Remember to use the same T (in kelvin) throughout AND remember to convert torr to atm in PV = nRT