A mixture of gases contains 2.00 mol of O2, 3.00 mol of N2, and 5.00 mol of He. The total pressure of the mixture is 850 torr. What is the partial pressure of each gas?
PV = nRT
V, R and T are constant
in other words the pressure of each is proportional to n
total moles = 2+3+5 = 10 mol
P of O2 = 850 (2/10)
P of N2 = 850 (3/10) etc
Wedc
To find the partial pressure of each gas in the mixture, we need to use the concept of mole fraction. The mole fraction of a gas is the ratio of the number of moles of that gas to the total number of moles in the mixture.
Let's calculate the mole fraction for each gas:
Mole fraction of O2 = (Number of moles of O2) / (Total number of moles)
Mole fraction of O2 = 2.00 mol / (2.00 mol + 3.00 mol + 5.00 mol)
Mole fraction of O2 = 2.00 mol / 10.00 mol
Mole fraction of O2 = 0.20
Similarly, we can calculate the mole fractions for N2 and He:
Mole fraction of N2 = (Number of moles of N2) / (Total number of moles)
Mole fraction of N2 = 3.00 mol / 10.00 mol
Mole fraction of N2 = 0.30
Mole fraction of He = (Number of moles of He) / (Total number of moles)
Mole fraction of He = 5.00 mol / 10.00 mol
Mole fraction of He = 0.50
Now, to find the partial pressure of each gas, we can multiply the mole fraction of each gas by the total pressure of the mixture:
Partial pressure of O2 = Mole fraction of O2 * Total pressure
Partial pressure of O2 = 0.20 * 850 torr
Partial pressure of O2 = 170 torr
Partial pressure of N2 = Mole fraction of N2 * Total pressure
Partial pressure of N2 = 0.30 * 850 torr
Partial pressure of N2 = 255 torr
Partial pressure of He = Mole fraction of He * Total pressure
Partial pressure of He = 0.50 * 850 torr
Partial pressure of He = 425 torr
Therefore, the partial pressure of O2 is 170 torr, the partial pressure of N2 is 255 torr, and the partial pressure of He is 425 torr.