Question

points Save Answer For the polyprotic acid histidine is the hydrogens in bold can be lost. When HisHy is rated with NaOH and it takes 45.0 mL to remove all protons possible in the titration curve, how many mL of NaOH are required to roach the first pa? Another way of asking this is when presented with a titration curve of HisHy where on the x-xs should one look (which volume of NaOH. If one wants to determine the first pa? HNCH OH но HEN NH A. 45 mi B. 7.5 ml 0.15 mL 0.225 ml E. 30 ml

Answer 1

The titration curve is PIE Pkaz plaz 3rd equir. point > 2nd equir point- → Ist equir. point pkai V2 rraort v=45 mL ty => X = 15 ml .'. 3x = V3 = 45 mL V = 15mL & v' = 4 1/2 = 7.5 mL (Ans. -B)