Dalton’s Law of Partial Pressures . To a tank containing N_{2} at 2.0 atm and O_{2} at 1.0 atm, we add an unknown quantity of CO_{2} until the total pressure within the tank is 4.6 atm. What is the partial pressure of the CO_{2} ?
Strategy : Dalton’s law tells us that the addition of CO_{2} does not affect the partial pressures of the N_{2} or O_{2} already present in the tank. The partial pressures of N_{2} and O_{2} remain at 2.0 atm and 1.0 atm, respectively, and their sum is 3.0 atm. The final total pressure within the tank, which is 4.6 atm, must be due to the partial pressure of the added CO_{2}.
