Two separate flasks are each filled with a gas at 25.0°C; the valve between them is opened and the gases are allowed to mix. What would be the final pressure in torr after mixing, if initially H2 is in the first flask (Volume = 4.000 L) at 271.8 torr and CCl4 is in the second flask (Volume = 1.000 L) at 372.7 torr?

"Key Concept:In gas mixtures we use Dalton's law, which states that the total pressure is the sum of the partial pressures of the individualt gases. In an ideal situation each gas should obey the ideal gas law. Each gas expands to the fill the two flasks. Use Boyle's law to predict the partial pressure of each after expansion. Add partial pressures."

1 answer

This is the long way around but I would do it this way but let me call your attention to the fact that CCl4 is NOT a gas at 25 C. Unless you clear up that part of the problem you are wasting your time on the rest of this.
Use PV = nRT for H2 and solve for n = number of mols.
Use PV = nRT for CCl4 gas and solve for n.
Add n H2 to n CCl4 = total n

Then PV = nRT, substitute the total n and the total V and final T and solve for P