Question
Question: To a 200 ml of 0.1 M weak acid HA solution 90 ml of 0.1 M solution of NaOH be added. Now, what volum...
To a 200 ml of 0.1 M weak acid HA solution 90 ml of 0.1 M solution of NaOH be added. Now, what volume of 0.1 M NaOH be added into above solution so that pH of resulting solution be 5. [(Ka(HA) = 10–5]
A
2 ml
B
20 ml
C
10 ml
D
15 ml
Answer
10 ml
Explanation
Solution
HA + NAOH ⟶ NaA + H2O
t = 0 20 9 0 0
t = t 11 0 9 0
t = 50% 10 0 10
10 ml NaOH is required.