Question

173 Mastery 1. Titration: pH's Str... 2 req Question о References Question Use the References to see important value of needed for this question Question 2. Titration: Weak A... Determine the pH during the titration of 17.6 mL of 0.291 M perchlorle acid by 8.42X10M barium hydroxide at the following points: 3. Titration: Weak B... (1) Before the addition of any barlumhydroxide 4. Interpretation of... (2) After the addition of 15.2 mL of barium hydroxide Submit (3) At the equivalence point (4) Afer adding 39.2 mL of barium hydroxide Submit Answer

Answer 1

BaloH is di acidic base and Hel Neutralisation s given by the tolowing equation clo is mono basic acid Ba 6H)2 ) + 2Hcl9 +2400 Ba clg) 7 PH-log ) Btore he addi ton of BaoH TH)= iclo = PH = - Log 6.29) O.291 M O 536 PH O54 b when 5.2 ml of Ba(oH) is added, M moles of Hc 10 molartyx Volume ml -O.291 Mx 17-6ml M moles of Pao4)= 8-42x 10 My 15.2ml1.2798 mmol. t nenthalise 5.1216 Mmol Mmoles of Hcl Yequired 1-2798 Mmol Ba6 2.5576 mmol 2x 1.2798 (5.1216 2.5596) mmol -2.562 Mmol 176ml + IS.2 ml- 32.8 ml mmol ml Remaining helg Total volume 2-562 mmol 32 8 me Moari of left over Hcl Fo0781M- - lo (0.0791) PH 1107 PH 1.1 9A the enui valene point shole acid is nentrakised by base, tclg 4 k shorg aud is 2 Base. BaH) Hene net o nic guahon on 0 B)10 PHo 10 7 Newhal) PH-7. 4 Atter addang 39.2 ml BalH),mmoles 42x1D MX39 2m) =3.30 Mmol = 2.5608 mmol Ba 6H) 5-1216 MMol Hcl Teqwires x5-1216

Left 3-30 2.5608) mmol Вабн) Over 2 0.7392 Mmol Total valume 17 6ml 39.2ml 56.8ml Molaby O.7392 mmol O.O130 M 56.8ml BaoH) Bat + 20H 2 2xOO130 M O.0260 M poH Log BA) -log 0.0260 M 15845 PH+ POH 14 PH 4-pH - 14 15845 =12.415 PH 12.4