Molar concentration of acid solution affected by addition of water?

Question

The wall of an Erlenmeyer flask is occasionally rinsed with water from the wash bottle during the analysis of the acid solution. How does this affect the reported molar concentration of the acid solution? Explain.

Answer 1

We must be in the same lab because I was just about to ask the same thing.  I think it doesn't affect the molar concentration because the NaOH is hygroscopic.