The wall of the flask is periodically rinsed with the previously boiled deionized water from the wash bottle. does this titrimetric technique result in an increase, a decrease, or have no effect on the reported acetic acid in the vinegar
This technique has no effect on the percent of acetic acid in the vinegar, as deionized water does not affect the number balance of H+ hydronium ions or OH- hydroxide ions. This is done just to make the endpoint reading easier.