Question

two sealed, rigid 5.0 l containers each contain a gas at the same temperature but at a different pressure. oxygen + nitrogen pressure =? oxygen pressure = 0.8 atm pressure = 1.0 atm also shown above are the results of transferring the entire contents of container 1 to container 2. no gases escape during the transfer. assuming ideal behavior, which statement is correct regarding the total pressure of the gases after they are combined? a the total pressure of the gases in the mixture is the sum of the initial pressures because gas pressure depends only on the total amount of gas and temperature and volume are held constant. b the total pressure of the gases in the mixture is lower than the sum of the initial pressures of oxygen and nitrogen because some of the energy of the particles will be lost due to an increase in the number of collisions. c the total pressure of the gases in the mixture is higher than the sum of the initial pressures of oxygen and nitrogen because the intermolecular forces that develop between oxygen and nitrogen molecules will increase the pressure. d the total pressure of the gases in the mixture cannot be determined because the actual value of the temperature is not given.

Explanation:

Step1: Recall Dalton's law of partial pressures

According to Dalton's law, for a mixture of non - reacting ideal gases, the total pressure of the gas mixture is the sum of the partial pressures of the individual gases. Given that the partial pressure of oxygen is $0.8$ atm and the partial pressure of nitrogen is $1.0$ atm, the total pressure $P_{total}=P_{O_2}+P_{N_2}$.

Step2: Calculate the total pressure

$P_{total}=0.8 + 1.0=1.8$ atm. Also, for ideal gases, the total pressure depends only on the sum of the number of moles (or partial pressures) of the gases in the mixture when volume and temperature are held constant.

Answer:

The total pressure in the mixture is the sum of the initial pressures of the gases in the mixture because pressure depends on the total number of gas particles and when volume and temperature are constant, the total pressure of a mixture of ideal gases is the sum of the partial pressures of the component gases. So the correct statement is A.