Chemistry: The Molecular Science (5th Edition)

Published by Cengage Learning
ISBN 10: 1285199049
ISBN 13: 978-1-28519-904-7

Chapter 15 - Additional Aqueous Equilibria - Questions for Review and Thought - Topical Questions - Page 693b: 36c


Methyl red is the most suitable, because it changes its color in acidic solutions, and the equivalence point of the titration between $NH_3$ and $HCl$ is in acidic solution.

Work Step by Step

$NH_3$ is a weak base and $HCl$ is strong acid; therefore, the pH at the equivalence point of their titration will be acid $(pH < 7)$. Analyzing the 3 given indicators on page 667, the one where the color changes in acidic solution is the most appropriate, so Methyl red is the correct answer.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.