Liquid A and liquid B form a solution that behaves ideally according to Raoult's law.The vapor pressures of the pure substances A and B are 233 torr and 135 torr,respectively.Determine the vapor pressure over the solution if 1.21 moles of liquid A is added to 5.30 moles of liquid B.
A)153 torr
B)188 torr
C)215 torr
D)760 torr
E)43.3 torr

Question

Quizplus · Accepted Answer

The vapor pressure of an ideal solution can be calculated using Raoult's law, which states that the vapor pressure of a solution is the sum of the vapor pressures of each component multiplied by its mole fraction in the solution. First, calculate the mole fractions of A and B:- Total moles = moles of A + moles of B = 1.21 + 5.30 = 6.51 moles- Mole fraction of A (X_A) = moles of A / total moles = 1.21 / 6.51- Mole fraction of B (X_B) = moles of B / total moles = 5.30 / 6.51Then, apply Raoult's law to find the total vapor pressure (P_total):- P_total = (X_A * P_A) + (X_B * P_B)- P_total = (1.21 / 6.51 * 233) + (5.30 / 6.51 * 135)Calculating the values:- P_total ≈ (0.186 * 233) + (0.814 * 135) ≈ 43.3 + 109.9 ≈ 153 torrTherefore, the vapor pressure over the solution is approximately 153 torr.

Liquid a and Liquid B Form a Solution That Behaves