Question

A mixture with H2 and He exerts a total pressure of 0.48 atm. If there is 1.0 g of H2 and 1.0 g of He in the mixture, what is the partial pressure (in atmospheres) of hydrogen?

Answer 1

Answer: 0.32 atm

Step-by-step explanation:

First convert the mass of H2 to moles using the molar mass.

(1.0 gram H2 ⋅ (1.0 mol H2 / 2.016 g H2)) ≈ 0.50 mol H2

Next, convert the mass of helium He to moles using the atomic mass.

(1.0 gram He ⋅ (1.0 mol He / 4.003 g He)) ≈ 0.25mol He

The total number of moles is about 0.75 moles . The partial pressure of a component of a gas mixture can be found by multiplying the mole fraction by the total pressure.

PH2 = XH2 × Ptotal

PH2 = (0.50 mol / 0.75 mol)(0.48 atm) = 0.32 atm

Answer 2

Partial pressure of hydrogen H₂ = 0.32 atm

Step-by-step explanation:

Given:

Total pressure = 0.48 atm

Find:

Partial pressure of hydrogen

Computation:

Number of mole of H₂ = 1 / 2 = 0.5 moles

Number of mole of He = 1 / 4 = 0.25 moles

Total moles = 0.5 + 0.25 = 0.75

Partial pressure of hydrogen H₂ = [moles / total moles] Total pressure

Partial pressure of hydrogen H₂ = [0.50 / 0.75]0.48 atm

Partial pressure of hydrogen H₂ = 0.32 atm