Please guys help with this question as soon as possible? Please guys help with t
ID: 1059168 • Letter: P
Question
Please guys help with this question as soon as possible?Please guys help with this question as soon as possible?
Please guys help with this question as soon as possible?
E) 4.60 5. When titrating a strong monoprotic acid with KoH at 25°C, the A) pH will be less than 7 at the equivalence point B) pH will be greater than 7 at the equivalence point C) pH will be equal to 7 at the equivalence point D) titration will require more moles of base than acid to reach the equivalence point E) at the equivalence point there will be an excess of the we base formed from the acid 6. A 100.0 mL sample of 0.18 M HCN is titrated with 0.27 M LiOH. Determine the pH of the solution after the addition of 66.67 mL of LioH (this is the equivalence point). Ka 6.2 x 10 A) 0.97 B) 13.03 C) 2.88 D) 11.12 E) 7.00
Explanation / Answer
5) when strong acid and strong base titration at equivalence point. pH = 7.0
answer = option C
6) millimoles of acid present = 100 x 0.18 = 18
millimoles of base added = 66.67 x 0.27 = 18.0
at equivalence point.
[salt] = 18 / 100 + 66.67 = 18 / 166.67 = 0.108 M
pH = 1/2 [pKw + pKa + log C]
pKa = - log Ka = - log [6.2 x 10-10] = 9.21
pH = 1/2 [14 + 9.21 + log 0.108]
pH = 1/2 [22.24]
pH = 11.12
answer = option D