Answer:
The partial pressure of N₂ in the mixture is 5.67 atm
Explanation:
According to Dalton's law, the partial pressure of a gas in a mixture of gases is given by the formula;
Partial pressure of gas A = Mole fraction of gas A × Total pressure of the mixture
We are required to calculate the partial pressure of N₂ in the mixture;
We are going to use the following simple steps;
Step 1. Calculating the total pressure of the mixture
We are given;
Moles of O₂ = 0.150 mol
Moles of N₂ = 0.116 mol
Moles of Ar = 0.211 mol
Thus , total moles of the mixture = 0.150 mol +0.116 mol + 0.211 mol
= 0.477 mol
Volume of the flask = 0.5 L
Temperature = 298 K
But; PV = nRT , where n is the number of moles and R is the ideal gas constant,0.082057 L.atm/mol.K
Thus; P = nRT ÷ V
= (0.477 mol × 0.082057 × 298 )÷ 0.5
= 23.328 atm
Step 2: Mole fraction of N₂
Mole fraction of a gas = Moles of a gas ÷ Total moles of the mixture
Mole fraction of N₂ = 0.116 mol ÷ 0.477 mol
= 0.243
Step 3: Partial pressure of N₂
P(N₂) = Mole fraction of N₂ × P(total)
= 0.243 × 23.328 atm
= 5.669 atm
= 5.67 atm ( 2 d.p.)
Therefore, the partial pressure of N₂ in the mixture is 5.67 atm
