Question

Solve a, b and 2

1. Calculate the pH during the titration of 10.00 mL of 0.400 M hypochlorous acid with 0.500 M NaOH. First what is the initial pH (before any NaOH is added)?
The K_a for HOCl is 3.0 x 10^-8 M. Answer is 3.96

a. What is the pH after 10.60 mL of NaOH are added?

b. What is the pH after 15.30 mL of NaOH are added?

2. Chloropropionic acid, ClCH₂CH₂COOH is a weak monoprotic acid with K_a = 7.94 x 10^-5 M. Calculate the pH at the equivalence point in a titration 41.0 mL of 0.60 M chloropropionic acid with 0.5 M KOH.

Answer 1

3-0xi08 M, pka - (1) Ka = - -log C3x108) IAi = 7.52 Initial pt-(a lag c) 1 t(7.52-lag (o4) =(7.52-leg(o-4)) = 1.92 2- = 3.96 No es molesef Hl= l0 x0.4=4 NO-et mmolejof Naot - 10 60x0.5-5 3 1-3 20.60 20 60 poH--lag60 = 1-20 PH-4-1201280 o e molesef Naot 15.30xo5765 COH T65-y 3 65 25.30 25-30 pOH 25.20 ptt = 14-0.84- 13 16 4-10 pH 7+굴 (pla + lge) MNIZMAS 41x06010.5xY = 1 + 2(4t0t le( a4-6 2m = 1+ I77= E.778.1