The amount of lactic acid, HC3H5O3, produced in a sample of muscle tissue was analyzed by reaction with hydroxide ion. Hydroxide ion was produced in the sample mixture by electrolysis. The cathode reaction is given below.
2 H2O(l) + 2 e ? ? H2(g) + 2 OH ? (aq)
Hydroxide ion reacts with lactic acid as soon as it is produced. The endpoint of the reaction is detected with an acid-base indicator. It required 111 s for a current of 13.2 mA to reach the endpoint. How many grams of lactic acid (a monoprotic acid) were present in the sample?