Question

A gas mixture at 0°C and 1.0atm contains 0.010mol of H2, 0.015mol of O2, and 0.025mol of N2. Assuming ideal behavior, what is the partial pressure of hydrogen gas (H2) in the mixture?
A. About 0.010atm, because there is 0.010mol of H2 in the sample.

B. About 0.050atm, because there is 0.050mol of gases at 0°C and 1.0atm.

C. About 0.20atm, because H2 comprises 20% of the total number of moles of gas.

D. About 0.40atm, because the mole ratio of H2:O2:N2 is 0.4:0.6:1.

Answer 1

Answer:

PH₂ = 0.2 atm

C) About 0.20atm, because H2 comprises 20% of the total number of moles of gas.

Explanation:

To determine the partial pressure of hydrogen gas (H2) in the mixture,

Partial pressure H₂ = Ptotal * xH₂

xH₂ = Mole fraction of H₂ = ∩H₂ / ( ∩H₂ + ∩O₂ + ∩N₂)

xH₂ = 0.01 / (0.01 + 0.015 + 0.025)

xH₂ = 0.01/0.05

xH₂ = 0.2

therefore

PH₂ = pT * xH₂

PH₂ = 1.0 atm * 0.2

PH₂ = 0.2 atm

so the correct option is C)  About 0.20atm, because H2 comprises 20% of the total number of moles of gas.