   # A solution is made by mixing 50.0 g acetone (CH 3 COCH 3 ) and 50.0 g methanol (CH 3 OH). What is the vapor pressure of this solution at 25°C? What is the composition of the vapor expressed as a mole fraction? Assume ideal solution and gas behavior. (At 25°C the vapor pressures of pure acetone and pure methanol are 271 and 143 torr, respectively.) The actual vapor pressure of this solution is 161 torr. Explain any discrepancies. ### Chemistry: An Atoms First Approach

2nd Edition
Steven S. Zumdahl + 1 other
Publisher: Cengage Learning
ISBN: 9781305079243

#### Solutions

Chapter
Section ### Chemistry: An Atoms First Approach

2nd Edition
Steven S. Zumdahl + 1 other
Publisher: Cengage Learning
ISBN: 9781305079243
Chapter 10, Problem 99AE
Textbook Problem
17 views

## A solution is made by mixing 50.0 g acetone (CH3COCH3) and 50.0 g methanol (CH3OH). What is the vapor pressure of this solution at 25°C? What is the composition of the vapor expressed as a mole fraction? Assume ideal solution and gas behavior. (At 25°C the vapor pressures of pure acetone and pure methanol are 271 and 143 torr, respectively.) The actual vapor pressure of this solution is 161 torr. Explain any discrepancies.

Interpretation Introduction

Interpretation:

The vapor pressure of the solution to be calculated.

The mole fraction for Acetone and Methanol to be calculated.

Concept introduction

Raoult’s law for ideal solution states that the mole fraction of the solvent is directly proportional to the vapor pressure of an ideal solution. Raoult’s law can be expressed by the equation,

Psolution=χsolventPosolvent

Where,

Psolution= observed vapor pressure of the solution

χsolvent= mole fraction of solvent

Posolvent= vapor pressure of pure solvent

Mole fraction is concentration of solution. It can be written as moles of the component divided by total moles in the solution.

Mole fraction =moles of the componenttotal moles in the solution

### Explanation of Solution

Record the given data

Amount of Acetone                    = 50g

Amount of Methanol                  = 50g

Vapor pressure of pure Acetone = 271 torr

Vapor pressure of pure Methanol = 143torr

Vapor pressure of the solution = 161torr

Temperature                              = 25°C

Vapor pressure of pure Acetone and Methanol, Vapor pressure of the solution, amount of Acetone and Methanol are recorded as shown.

To calculate vapour pressure of the solution.

Ptotal= PMethanol+PAcetone

= 0.644 (143 torr) + 0.356 (271torr)

= 92.1torr + 96.5torr =188.6 torr

To calculate vapour pressure of the solution at gaseous state.

χVAcetonePAcetonePtotal96.5 torr188.6 torr=0.512

χVMethanol= 1

### Still sussing out bartleby?

Check out a sample textbook solution.

See a sample solution

#### The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started

Find more solutions based on key concepts
Over-the-counter drugs for obesity are most often effective and pose little risk.

Nutrition: Concepts and Controversies - Standalone book (MindTap Course List)

The smallest unit of any substance is the _____. a. atom b. molecule c. cell

Biology: The Unity and Diversity of Life (MindTap Course List)

What are derived units?

An Introduction to Physical Science

Determine the number of equivalents in 211mL of 0.50N hydrochloric acid.

Introductory Chemistry: An Active Learning Approach

What two forces drive the cocoon nebula away from a protostar?

Foundations of Astronomy (MindTap Course List)

Two long, parallel wires carry currents of I1 = 3.00 A and I2 = 5.00 A in the directions indicated in Figure P2...

Physics for Scientists and Engineers, Technology Update (No access codes included) 