When performing a titration of a monoprotic acid and a monoprotic base, water can not be added to the titrant but water can be added to the analyte. To prove this statement to myself, I decided to analyze the equation for a hypothetical titration where the acid is the analyte and the base is the titrant:
[Acid] = (Volume of Base) $\cdot$ [Base] / (Volume of Acid)
So, if water is added to the base in the burette, the volume of base would increase but the molarity of the base would decrease and the effects seem to cancel out, leading to the same [Base] calculation. However, when water is added to the acid in the flask, the volume of acid increases which would lead to a decrease in the [Acid] calculation.
This contradicts the common protocol and knowledge when adding water to the burette or flask. Many answers I have seen state that the moles of acid and base stay constant if water is added to the analyte; however, wouldn't this also increase the volume of analyte and skew the calculation of [Acid]?
It would be awesome if someone could explain the effects of adding water to the burette and analyte on the equation above.