A container of N₂ has a pressure of 10 kPa and a volume of 20 L. As second container of O₂ has a pressure of 20 kPa and a volume of 10 L. The containers are connected to each other so that the gases can mix freely. What is the final pressure of the gas mixture?

42.5 mL of H₂ gas are collected by the displacement of water at a temperature of 25.0C and an atmospheric pressure of 765 mm Hg. The vapour pressure of H₂O at 25.0C is 23.8 mm Hg. How many moles of H₂ are collected?

also for the 2nd q: what volume would the dry gas produced occupy?

thanks