Chapter 22, Problem 40R

To determine

To Compare: The pH of a dilute solution of HCl with the pH of a concentrated solution of the same acid.

Explanation of Solution

Introduction: Bases are compounds that gives ${\text{OH}}^{-}$ ions in water or accepts ${\text{H}}^{+}$ ions from acids.

HCl is a strong acid so it dissociates completely in an aqueous solution.

The pH of a solution is a measure of the concentration of ${\text{H}}^{+}$ ions in the solution.

The concentration of asolution is related to the amount of acid dissolved in the solution.

In a dilute HCl solution, the amount of HCl acid in the solution is less compared to the amount of water. Hence, the concentration of ${\text{H}}^{+}$ ions produced by the acid decreases. Therefore, its pH increases.Higher the value of pH, less acidic is the solution.

Hence, a dilute solution of HCl is less acidic than the concentrated solution of the same acid.

Conclusion:The pH of a dilute solution of HCl is greater than the pH of a concentrated solution of the same acid.