Final answer:
The indicator may not be suitable for the specific titration if it changes color at a pH that is 0.8 higher than the equivalence point indicated by a pH meter. It is important to choose an indicator with a color change interval that includes the pH range of the titration, including the equivalence point.
Step-by-step explanation:
The most likely explanation for the indicator changing colors at a pH that is 0.8 higher than the equivalence point indicated by a pH meter is that the chosen indicator is not suitable for that specific titration. pH indicators have a specific range of pH values at which they change color, known as the color change interval. If the pH at the equivalence point falls outside of this range, the indicator will not accurately indicate the endpoint.
For example, if the pH at the equivalence point is higher than the upper limit of the indicator's color change interval, the indicator may change color before reaching the equivalence point. This could result in an apparent discrepancy between the indicator's color change and the pH indicated by the pH meter.
To ensure accurate results, it is important to choose an indicator that has a color change interval that encompasses the pH range of the titration, including the equivalence point.