Consider a mixture of two gases,A and B, confined in accosted vessel. A quantity of a third gas C, is added to the same vas sekar the same temperature. How does the addition of gas C affect the following: a. The partial pressure of gas A. b. The total pressure in the vassal, c. The mole fraction of gas B
pA is unchanged.
Ptotal is increased.
XB is decreased since total mols is increased.
a. The partial pressure of gas A:
The addition of gas C does not directly affect the partial pressure of gas A. The partial pressure of a gas is determined by the number of moles and the temperature. As long as the temperature remains constant and there are no reactions or changes in volume, the partial pressure of gas A will remain unchanged.
b. The total pressure in the vessel:
The addition of gas C will increase the total pressure in the vessel. When a gas is added to a confined space, it increases the number of gas molecules present, leading to more frequent collisions with the walls of the vessel. This increase in collisions results in an increased total pressure inside the vessel.
c. The mole fraction of gas B:
The mole fraction of gas B will depend on the amount of gas C added to the mixture. Assuming the total number of moles of gases A, B, and C remains constant, the mole fraction of gas B will decrease. This is because the addition of gas C increases the total number of moles in the mixture, diluting the mole fraction of each individual gas.
To understand how the addition of gas C affects the different parameters, we need to consider the principles of Dalton's law of partial pressures and the concept of mole fraction.
a. The partial pressure of gas A:
According to Dalton's law of partial pressures, in a mixture of gases, the total pressure exerted is equal to the sum of the partial pressures of each gas. Initially, gas A contributes to the total pressure with its partial pressure. When gas C is added to the mixture, it will also exert its own partial pressure.
The partial pressure of gas A will remain unchanged because the addition of gas C does not directly affect gas A. Gas A's molecules would continue exerting the same pressure as they did before the addition of gas C.
b. The total pressure in the vessel:
When gas C is added to the vessel, it will contribute its own partial pressure to the total pressure. Therefore, the total pressure in the vessel will increase. The increase in the total pressure is due to the addition of the additional gas molecules exerting their pressure alongside the initial gases.
The total pressure will be the sum of the partial pressures of gases A, B, and C.
c. The mole fraction of gas B:
The mole fraction of a gas in a mixture is the ratio of the number of moles of gas B to the total number of moles in the mixture.
When gas C is added to the vessel, the total number of moles in the mixture increases. However, the mole fraction of gas B will remain unchanged unless the amount of gas B is altered.
If the number of moles of gas B remains the same, the ratio of moles of gas B to the total number of moles in the mixture (mole fraction) will remain constant. Therefore, the addition of gas C will not affect the mole fraction of gas B.
In summary:
a. The partial pressure of gas A remains unchanged.
b. The total pressure in the vessel increases.
c. The mole fraction of gas B remains unchanged unless the amount of gas B is altered.