A chemist is studying a closed, rigid container that holds a mixture of two ideal gases, X and Y, at constant temperature. The total pressure of the system is measured to be 1.00 atm. The chemist wishes to understand how the composition of the mixture affects the individual gas pressures.
(1) Describe, in words, the relationship between the mole fraction of a gas in a mixture and its partial pressure. Include an explanation of why this relationship holds for ideal gases in a fixed volume at constant temperature.
(2) If an additional 0.20 mol of an inert gas Z is injected into the container at the same temperature without changing the volume, explain qualitatively how (if at all) the partial pressures of X and Y will change. Justify your answer in terms of mole fractions and total pressure.