Question

a mixture of n₂, o₂ and he have mole fractions of 0.25, 0.65, and 0.10, respectively. what is the pressure of n₂ if the total pressure of the mixture is 3.9 atm?
○ 2.5 atm
○ 3.9 atm
○ 0.975 atm
○ 1.00 atm

Explanation:

Step1: Recall Dalton's Law

For a gas mixture, the partial pressure of a gas ($P_i$) is given by $P_i = X_i \times P_{total}$, where $X_i$ is the mole fraction of the gas and $P_{total}$ is the total pressure.

Step2: Identify values for $\ce{N2}$

Mole fraction of $\ce{N2}$ ($X_{\ce{N2}}$) = 0.25, total pressure ($P_{total}$) = 3.9 atm.

Step3: Calculate partial pressure of $\ce{N2}$

Using the formula $P_{\ce{N2}} = X_{\ce{N2}} \times P_{total}$, substitute the values: $P_{\ce{N2}} = 0.25 \times 3.9$.
Calculate the product: $0.25 \times 3.9 = 0.975$ atm.

Answer:

0.975 atm