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Dalton\'s law states that the total pressure P_total, of a mixture of gases in a

ID: 519762 • Letter: D

Question

Dalton's law states that the total pressure P_total, of a mixture of gases in a container equals the sum of the pressures of each individual gas: P_total = P_1 + P_2 + P_3 + ... The partial pressure of the first component, P_1, is equal to the mole fraction of this component, X_1, times the total pressure of the mixture: P_1 = X_1 times P_total The mole fraction, X. represents the concentration of the component in the gas mixture, so X_1 = moles of component 1/total moles in mixture A gaseous mixture of O_2 and N_2 contains 40.8 nitrogen by mass. What is the partial pressure of oxygen in the mixture if the total pressure is 545 mmHg? Express you answer numerically in millimeters of mercury.

Explanation / Answer

If N2 is 48gms then O2 is 52gms

Mole of N2 = 48/28 = 1.714moles

Moles of O2 = 52/32 = 1.625moles

Mole fraction of oxygen = 1.625/1.714+1.625 = 1.625/3.339 = 0.487

Partial pressure of oxygen = mole fraction of oxygen * total pressure.

= 0.487*545mmHg

Poxygen = 265.24mmHg.