A 0.500-gram sample of a weak, nonvolatile monoprotic acid, HA, was dissolved in sufficient water to make 50.0 milliliters of solution. The solution was then titrated with a standard NaOH solution. Predict how the calculated molar mass of HA would be affected (too high, too low, or not affected by the following laboratory procedures. Explain each of your answers.
a. After rinsing the buret with distilled water, the buret is filled with the standard NaOH solution; the weak acid HA is titrated to its equivalence point.
b. Extra water is added to the 0.500-gram sample of HA.
(a) An indicator that changes color at pH 5 is used to signal the equivalence point.
(b) An air bubble passes unnoticed through the tip of the buret during the titration.