Chapter 24, Problem 122A

Interpretation Introduction

Interpretation: To interpret the changes observed at the endpoint of acid-base titration.

Concept introduction: Titration is a quantitative analysis that is used to determine the concentration of an unknown sample.

Answer to Problem 122A

At the end point of an acid-base titration, the indicator must change its color.

Explanation of Solution

In an acid-base titration, there comes a point when the moles of hydrogen ions are similar to the moles of hydroxide ions, and this point is termed an equivalence point. The indicator that is used at the time of titration must change its color around the pH of the equivalence point.

The point that depicts the color change of an indicator is the end point of the titration.

Conclusion

Thus, at the end point of an acid-base titration, the indicator must change its color.