A mixture of three gases has a total pressure of 1,380 mm Hg at 298 K. The mixture is analyzed and is found to contain 1.27 mol CO2, 3.04 mol CO, and 1.50 mol Ar. What is the partial pressure of Ar

Considering the Dalton's law, the partial pressure of Ar is 356.04 mmHg.

The pressure exerted by a particular gas in a mixture is known as its partial pressure.

So, Dalton's law states that the total pressure exerted by a gaseous mixture is equal to the sum of the pressures that would be exerted by the gases if each were present and occupied the total volume.

In other words, each gas in the mixture acts as if it were alone, so the pressures of each gas that make up a mixture add up:

PT = P₁ + P₂ + ... + Pₙ

Dalton's partial pressure law can also be expressed in terms of the mole fraction of the gas in the mixture. The mole fraction is a dimensionless quantity that expresses the ratio of the number of moles of a component to the number of moles of all the components present.

So in a mixture of two or more gases, the partial pressure of gas A can be expressed as:

PA = xA× PT

The Molar Fraction is a way of measuring the concentration that expresses the proportion in which a substance is found with respect to the total moles of the solution.

The mole fraction of the elements of a compound is calculated as a quotient between the number of moles of each of the different elements present in the compound and the total number of moles.

So to calculate the partial pressure of Ar you know that:

Then, the partial pressure of Ar can be calculated as:

356.04 mmHg

Finally, the partial pressure of Ar is 356.04 mmHg.

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P(Ar) = 358.8 mmHg

Explanation:

Given data:

Total pressure of gas = 1380 mmHg

Moles of CO₂ = 1.27 mol

Moles of CO = 3.04 mol

Moles of Ar = 1.50 mol

Partial pressure of Ar = ?

Solution:

Formula:

P(Ar) = [n₁/nt] Pt (1)

n₁ = moles of Ar

nt = total number of moles

Pt = total pressure

Now we will calculate the total number of moles.

nt = 1.27 mol +3.04 mol +1.50 mol

nt = 5.81 mol

Now we put the values in formula (1)

P(Ar) = [n₁/nt] Pt

P(Ar) = [1.50/5.81] 1380 mmHg

P(Ar) = 0.26 ×1380 mmHg

P(Ar) = 358.8 mmHg