If your experimental molar concentration of NaOH were not close to the accepted value molarity of NaOH if the true value of the molar concentration were 0.1 021 M what are two likely reasons for the discrepancy. Do not simply say "human error." Explain clearly and specify whether the cause of error would lead to a higher or lower experimental molar concentration of NaOH ?

One of the errors maybe in the mixing of the solution in the burette and the solution in the conical flask or beaker which is most likely the base. when this is not properly mixed, it will affect the equivalence point or the end point of the experiment.

Also there will be a discrepancy in the color at end point as a result of improper mixing, this will have an effect on the indicators used in the titration experiment. Indicators are acid-alkaline organic base that change color over a particular pH range, but when there is an errors in mixing, no sharp color change will be observed.

In the end, the erros in mixing will affect the concentration of the sodium hydroxide by way of lowering the concentration of the base.