Question

In this experiment, you will titrate an unknown acid with a base. It will be important for you to understand certain things about this titration in order to identify successfully your unknown. For all of the following questions, assume you are titrating an unknown monoprotic acid, HA, with NaOH solution. 0.146 g of HA is added to a beaker and made into a solution with ~100 mL of distilled water. As the titration proceeds, you keep track of the pH whenever either 1 mL of 0.368 M NaOH is added, or the pH rises 1 unit (whichever came first). You note the endpoint (either by the color change of an indicator, or a sharp rise in pH from the pH meter) after 19.52 mL of NaOH delivered. What is the Molar Mass of the unknown acid HA? Enter your answer as a number with at least 3 sig figs. Assume that the units are g/mole (remember that the units of Molar Mass are grams/mole. You know the mass (g) of weak acid and the titration helps us find the moles of weak acid since the moles of monoprotic acid equals the moles of base at the equivalence point if the following equation is 1:1) HA(aq) + NaOH(aq) <--> H2O(l) + NaA(aq)

Answer 1