Suppose that you are going to collect H₂ gas produced from the reaction of an acid with a metal such as zinc.

This reaction gives off heat, so the temperature of the solution will increase as the reaction proceeds. You need to know the partial pressure of the H₂ you generate as precisely as possible. What will you need to account for in your calculation? What things would you need to measure to make accurate calculations? What information would you need to look up?