Question

The ratio of acid strength of HOCN and HCN is about

Given K_a of HOCN = 1.2 × 10^–4 and K_a of HCN = 4.2 × 10^–10

• A. 548 : 1
• B. 1 : 548
• C. 2.86 × 10⁵ : 1
• D. 2.86 × 10⁴ : 1

Answer 1

Answer: (A)

548 : 1

Answer 2

$\frac { \left[ \mathrm { H } ^ { + } \right] _ { \mathrm { HOCN } } } { \left[ \mathrm { H } ^ { + } \right] _ { \mathrm { HCN } } }$ =

= $\left( \frac { 1.2 \times 10 ^ { - 4 } } { 4.2 \times 10 ^ { - 10 } } \right) ^ { 1 / 2 }$ = 535