Question

A student performs three trials of a titration of an acid with an unknown concentration. She compares her measured concentration to the actual value, and calculates a 25% error. Assuming she has performed all of the calculations correctly, name one aspect of her methods that may have led to such a high error.

Answer 1

Answer:

There are many errors possible while titrating the acid of an unknown concentration with a base like NaOH.

Main error that leads to the error in results is misreading of the end point volume .

End point is when the reaction between the analyte and solution of known concentration has stopped .

Sometimes Burette is not straight enough to read the volume of the end point. One way to misread the volume of burette is by looking at the burette volume at an angle .

From above , volume seems to be higher. Indicators are used to indicate the color change of the reaction. In Acid-Base titrations , indicators first lighten up then changes its color.

So, error may have occurred in wrongly judging of the end point by color change of the indicator .