   Chapter 13, Problem 27PS

Chapter
Section
Textbook Problem

Pure ethylene glycol, HOCH2CH2OH, is added 2.00 kg of water in the cooling system of a car. The vapor pressure of the water in the system when the temperature is 90 °C is 457 mm Hg. What mass of glycol was added? (Assume the solution is ideal. See Appendix G for the vapor pressure of water.)

Interpretation Introduction

Interpretation: The mass of glycol added to 2kg of water has to be identified.

Concept introduction:

Raoult’s law: The vapor pressure of the solvent over the solution Psolvent is proportional to the mole fraction of the solvent. The ideal solution obeys the Raoult’s law.

PsolventχsolventPsolvent,where,Psolventisthevapor pressure of the solvent over the solution,χsolventis mole fraction of solvent in solution, Psolvent is the vapor pressure of the pure solvent.

Explanation

Given data:

Massofwater=2kgPsolution=457mmHgPsolvento (vapor pressure of water at 90oC ) =525.8 mmHg

Molesofwater=MassMolarmass=2000g18g/mol=111.11mol

Psolution= χsolventPsolvento,457mmHg=(χwater)(525.8 mmHg)χwater   = 0.869

Molefraction=nwaternglycol+nwater

0.869=nwaternglycol+nwater0.869(nglycol+nwater)=nwater(0

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

What is hereditarianism, and what is the invalid assumption it makes?

Human Heredity: Principles and Issues (MindTap Course List)

What is meant by biological evolution?

Human Biology (MindTap Course List)

How does binge-eating disorder differ from bulimia nervosa?

Nutrition Through the Life Cycle (MindTap Course List) 