Question

1. a 300 - milliliter container that is filled with 100 milliliters of oxygen and 200 milliliters of hydrogen has a total pressure of 75 kpa. what is the partial pressure of the oxygen? a) 10 kpa b) 20 kpa c) 25 kpa d) 50 kpa

Explanation:

Step1: Calculate mole - fraction of oxygen

The mole - fraction ($X_{O_2}$) of a gas in a mixture is given by the ratio of the volume of the gas to the total volume of the mixture. The total volume of the gas mixture $V_{total}=100 + 200=300$ mL. The volume of oxygen $V_{O_2}=200$ mL. So, $X_{O_2}=\frac{V_{O_2}}{V_{total}}=\frac{200}{300}=\frac{2}{3}$.

Step2: Use Dalton's law of partial pressures

Dalton's law states that the partial pressure of a gas ($P_{O_2}$) in a mixture is the product of its mole - fraction ($X_{O_2}$) and the total pressure ($P_{total}$). Given $P_{total}=75$ kPa. Then $P_{O_2}=X_{O_2}\times P_{total}=\frac{2}{3}\times75$ kPa.
$P_{O_2}=50$ kPa.

Answer:

D. 50 kPa