Final answer:
The student inquiry is about calculating partial pressures in a gas mixture using Dalton's law of partial pressures and mole fractions. Mole fraction is used to determine the share of each gas in the total pressure, and the example given illustrates how to calculate partial pressures for hydrogen and helium in a mixture.
Step-by-step explanation:
The question appears to relate to Dalton's law of partial pressures and the concept of mole fraction in a gas mixture. Mole fraction is the ratio of the number of moles of a component in a mixture to the total number of moles of all components. The partial pressure of a gas in a mixture is determined by its mole fraction and the total pressure of the mixture. Dalton's Law states that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the individual gases.
To calculate the partial pressure of a gas in a mixture,
- Find the mole fraction of the gas by dividing the number of moles of the gas by the total number of moles in the mixture.
- Multiply this mole fraction by the total pressure exerted by the mixture to obtain the partial pressure of the gas.
For example, in a mixture of 1 mol of hydrogen gas (H2) and 3 mol of helium (He), if the total pressure is 2400 mm Hg, the partial pressures are calculated as follows:
- Partial pressure of H₂ (PH₂) = mole fraction of H₂ × total pressure = (1 / (1+3)) × 2400 mm Hg = 600 mm Hg
- Partial pressure of He (PHe) = mole fraction of He × total pressure = (3 / (1+3)) × 2400 mm Hg = 1800 mm Hg
The partial pressures of the gases do not change upon mixing if the conditions (temperature and volume) remain constant.