Question

Name Desk Date, Laboratory Instructor Titration Curves of 26 Pre-lab Polyprotic Acids Questions tory, you should be able to answer the Before beginning this experiment in the labora following questions. 1. What is a polyprotic acid? If 10.7 mL of 0.105 M NaOH is required to reach the first equivalence point of a solution of citric acid (H,CH,O,), how many milliliters of NaOH are required to completely neutralize this solution? 2. 3. How many millimoles of NaOH will react completely with S0 mL of IS MH,C,O 4. How many moles of H,o are present in 250 mL of a 0.30 M solution of H,SO,7 5. Why is it necessary to standardize a pH meter? 6. If the pH at one-half the first and second equivalence points of a dibasic acid is 4.20 and 7.34, respectively, what are the values for pkol and pK,2? From pkol and pK2, calculate the K,j and K,2

Answer 1

1) A polyprotic acid is one which can furnish more than one proton an aqueous medium or in otherwords acid that contains more than one replacable hydrogen.

examples- H₂SO₄ provides 2 proton (H⁺) called as diprotic

H₂CO₃ provides 2 proton (H⁺) called as diprotic

H₃PO₄ provides 3 proton (H⁺) called as triprotic