Question

What is a the partial pressure of helium gas in a closed system containing 0.775 mol of helium gas, 1.12 mol of methane gas, and 0.592 mol of hydrogen gas?

The system containing the three gases has a total pressure of 1.50 atm.

Answer 1

0.467 atm

Step-by-step explanation:

Step 1: Calculate the total number of moles

The total number of moles is equal to the sum of number the moles of each gas.

n = nHe + nCH₄ + nH₂

n = 0.775 mol + 1.12 mol + 0.592 mol = 2.49 mol

Step 2: Calculate the mole fraction of He

χHe = nHe / n

χHe = 0.775 mol / 2.49 mol

χHe = 0.311

Step 3: Calculate the partial pressure of He

We can use the following expression.

pHe = P × χHe

pHe = 1.50 atm × 0.311

pHe = 0.467 atm