"In carrying out a titration of a hydrochloric acid solution with a standard sodium hydroxide solution, a student went beyond the end point before reading the volume on the burette. That is, the volume used was larger than the volume required to reach the end point. How will this error affect the calculated concentration of the hydrochloric acid?"

The calculated concentration of HCl will be less than actual.

Explanation:

Suppose during titration, the HCl was taken in burette and the NaOH in the volumetric flask.

Now we will use equivalence formula for the calculation of concentration of HCl.

Where L.H.S is for hydrochloric acid and R.H.S is for sodium hydroxide. The terms N and V represent normality and volume respectively.

If we calculate for

We see that if the volume of the HCl is greater then the concentration of the HCl will be reduced.