Acids & Bases Problem Set

Acids & Bases Problem Set

Question 7: Neutralizing a basic solution

Tutorial to help answer the question

How many ml of a 0.4 M HCl solution are required to bring the pH of 10 ml of a 0.4 M NaOH solution to 7.0 (neutral pH)?

Note: HCl and NaOH both completely dissociate in water (i.e., no pK_a calculation is necessary).

A. 4

B. 40

C. 10

D. 20

E. 2

Tutorial

Neutralizing a basic solution

This question does not require any complicated calculations, but rather can be solved by considering how acids and bases work. In this case, both the acid and the base solutions are at the same concentration. Also, as noted in the question itself, NaOH and HCl completely dissociate.

Thus, a neutral pH can be achieved by adding an equal amount of the acid solution to the base solution.

The Biology Project
Department of Biochemistry and Molecular Biophysics
The University of Arizona
January 6, 1999
Revised: October 2004
Contact the Development Team