Interpretation: The mole fraction of benzene in the original solution needs to be determined.
Concept Introduction: The ratio of number of moles of a substance in a compound to the total number of moles of the compound is said to be mole fraction. The formula is:
Answer to Problem 129CP
The mole fraction of benzene in the original solution is
Explanation of Solution
Given:
Vapor pressure of pure benzene is 750.0 torr and of pure toluene is 300.0 torr.
The mole fraction in the given vapor is 0.714.
Since, the sum of all mole fractions in a given mixture is 1 so, the mole fraction of toluene in solution II is:
Where
Substituting the value of mole fraction of benzene in solution II as:
The formula for a partial pressure of a gas in mixture is:
Where
Rearranging the equation as:
The above equation is written in terms of benzene in solution II as:
According to Raoult’s Law,
Where
The value for,
Solving for
Thus, the mole fraction of benzene in solution II is 0.5 and the mole fraction of toluene in solution II is (1.0 -0.5) is 0.5.
Now, in order to calculate the mole fraction of benzene in original solution:
Let
Now, the equation (1) for solution (I) can be written as:
Rewriting the above equation using Raoult’s law as:
Since, the solution behaves ideally, so
Substituting the values:
Solving for
Hence, the mole fraction of benzene in the original solution is
Want to see more full solutions like this?
Chapter 17 Solutions
Chemical Principles
- Temperature influences solubility. Does temperature have the same effect on all substances? Justify your answer. (Hint: Consider Le Chateliers principle.)arrow_forwardThe vapor pressures of several solutions of water-propanol (CH3CH2CH2OH) were determined at various compositions, with the following data collected at 45C: H2O Vapor pressure(torr) 0 74.0 0.15 77.3 0.37 80.2 0.54 81.6 0.69 80.6 0.83 78.2 1.00 71.9 a. Are solutions of water and propanol ideal? Explain. b. Predict the sign of Hsoln for water-propanol solutions. c. Are the interactive forces between propanol and water molecules weaker than, stronger than, or equal to the interactive forces between the pure substances? Explain. d. Which of the solutions in the data would have the lowest normal boiling point?arrow_forwardThe freezing point of 0.10 M KHSO3 is -0.38C. Which of the following equations best represents what happens when KHSO3 dissolves in water? (a) KHSO3(s)KHSO3(aq) (b) KHSO3(s) K+(aq)+HSO3(aq) (c) KHSO3(s) K+(aq)+SO32(aq)+ H+(aq)arrow_forward
- The organic salt [(C4H9)4N][ClO4] consists of the ions (C4H9)4N+ and ClO4. The salt dissolves in chloroform. What mass (in grams) of the salt must have been dissolved if the boiling point of a solution of the salt in 25.0 g chloroform is 63.20 C? The normal boiling point of chloroform is 61.70 C and Kb = 3.63 C kg mol1. Assume that the salt dissociates completely into its ions in solution.arrow_forwardA solution is made by dissolving 34.0 g of NaCl in 100 g of H2O at 0C. Based on the data in Table 8-1, should this solution be characterized as a. saturated or unsaturated b. dilute or concentratedarrow_forwardThe osmotic pressure of a solution containing 7.0 g of insulin per liter is 23 torr at 25 C. What is the molar mass of insulin?arrow_forward
- ChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage LearningChemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage Learning
- Chemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage LearningPrinciples of Modern ChemistryChemistryISBN:9781305079113Author:David W. Oxtoby, H. Pat Gillis, Laurie J. ButlerPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning