The dissociation constants for acetic acid and HCN at 25 are 1.5 10-5 and 4.5 10-10 respectively. The equilibrium constant for the equilibrium CN- + CH3COOH HCN + CH3COO- would be
- 3.3 10-5
- 3.3 10-4
- 3.3 104
- 3.3 105
Answer
(3) 3.3 104
Solution
CH3COOH CH3COO- + H+; K1 = 1.5 10-5
CN- + H+ HCN; K2 = 14.5 10-10
Adding: CN- + CH3COOH HCN + CH3COO-
⇒ K = K1 K2 = 1.5 10-54.5 10-10
= 3.3 104
Answer: (3)