Question
Question: The pH of 0.5 (M) Ba(CN)<sub>2</sub> solution is- Given pK<sub>b</sub> of CN<sup>–</sup> = 9.3...
The pH of 0.5 (M) Ba(CN)2 solution is-
Given pKb of CN– = 9.3
A
8.35
B
3.35
C
9.35
D
9.5
Answer
9.35
Explanation
Solution
Ba2+ is not hydrolysed , CN– = 1 (M)
CN– + H2O ⇄HCN + OH–
pH = 21 (pKw + pKa + log c)
pH = 21 (pKw + pKa) since c = 1(M)
pH = 21 (2pKw – pKb) = 21 (28 – 9.3)
pH = 21 (28 – 9.3) = 9.35