Concept explainers
Interpretation: The reason for the pH of an aqueous solution of NaCl doesn’t change upon dilution needs to be explained.
Concept Introduction:The pH of an aqueous solution is calculated as follows:
pH = -log [H3O+]
Where [H3O+] is concentration of hydroxonium ions in the solution.
Answer to Problem 6E
The pH of the solution of NaCl doesn’t change upon dilution because the dilution doesn’t alter (increase or decrease) the H3O+ concentration of the solution.
Explanation of Solution
Sodium chloride, NaCl ionizes in an aqueous solution as below.
Since the solution is aqueous, water, H2O is also present in the solution in large excess. However, H2O is a poor electrolyte and remains unionized in an aqueous solution.
The dilution of a solution simply means that more water, H2O is added to the solution so that the molar concentration of the solute (here electrolyte, NaCl) decreases; however, the amount (in moles) of NaCl remains unchanged upon dilution.
Since the dilution of the given solution of NaCl only introduces additional H2O in the solution which remains undissociated, hence, no H3O+ is added or removed from the solution upon dilution and thus, the pH of the solution remains unaltered.
The pH of the solution doesn’t change upon dilution because there is no change in the concentration of hydrogen ion takes place.
Chapter U4 Solutions
Living by Chemistry
Additional Science Textbook Solutions
Chemistry: Structure and Properties (2nd Edition)
Chemistry: Structure and Properties
Essential Organic Chemistry (3rd Edition)
Chemistry: An Introduction to General, Organic, and Biological Chemistry (13th Edition)
Organic Chemistry
Chemistry: The Central Science (13th Edition)
- ChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage LearningChemistryChemistryISBN:9781259911156Author:Raymond Chang Dr., Jason Overby ProfessorPublisher:McGraw-Hill EducationPrinciples of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning
- Organic ChemistryChemistryISBN:9780078021558Author:Janice Gorzynski Smith Dr.Publisher:McGraw-Hill EducationChemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningElementary Principles of Chemical Processes, Bind...ChemistryISBN:9781118431221Author:Richard M. Felder, Ronald W. Rousseau, Lisa G. BullardPublisher:WILEY