Chapter 18, Problem 87A

When might a pH meter be better than an indicator to determine the end point of an acid-base titration?

Interpretation Introduction

Interpretation:

The condition when $pH$ meter is better than indicator in acid-base titration is to be determined.

Concept introduction:

Acid-base indicator is a chemical which changes its color on neutralization.

There are various acid-base indicators like phenolphthalein, methyl orange, bromocresol green, bromocresol purple, phenol red

All have a specific $pH$ value on which solution changes its color that is called as equivalence point

Answer to Problem 87A

$pH$ meter is better than indicator in acid-base titration when there is no indicator available at or close to equivalence point.

Explanation of Solution

Acid-base indicator is helpful if it changes its color at equivalence point. Thus, if for a particular titration there is no indicator in the range of equivalence point, $pH$ meter is better to use.

Conclusion

$pH$ meter is better than indicator in acid-base titration when there is no indicator available at or close to equivalence point.