Question

turned dark pink? an indicator was added to the solution which resulted in a color - change signifying that the acid - base neutralization titration was complete. what property of the solution changes when this color change occurs? if it would have taken more than three trials to get values for the molar mass to agree within one percent, what are some possible sources of error that could have occurred? iv. conclusion

Explanation:

Step1: Identify property in acid - base titration

In an acid - base neutralization titration, the pH of the solution changes. When the indicator changes color, it means the equivalence point (neutralization) has been reached and the pH has reached a specific value for that indicator.

Step2: List possible sources of error for molar mass

1. Inaccurate measurements: Incorrect volume measurements of the titrant or the sample solution can lead to errors in calculating the molar mass. For example, misreading the burette or pipette.
2. Impurities: The presence of impurities in the sample can affect the results. Impurities may react with the titrant or change the properties of the solution, leading to incorrect molar mass values.
3. Indicator error: The indicator may not change color exactly at the equivalence point. Different indicators have different pH ranges for color - change, and if not chosen correctly, it can cause errors in determining the end - point of the titration and thus errors in molar mass calculations.

Answer:

• The property that changes when the color change occurs is pH.
• Possible sources of error: Inaccurate measurements, impurities in the sample, indicator error.