Question

What is (h+) of a solution that is 0.1 m hcn and 0.2m nacn?

Answer 1

your question is incomplete. A complete question is -> What is (H+) of a solution that is 0.1M HCN and 0.2M NaCN?

NaCN?(Ka for HCN = 6.2 × 10^-10 )

solution : solution of HCN and NaCN is buffer solution.

using formula, pH = pKa + log[salt ]/[acid]

= -log(6.2 × 10^-10) + log[NaCN]/[HCN]

= 10 - log(6.2) + log(0.2/0.1)

= 10 - log(6.2) + log(2)

≈ 9.5

now, from Arrhenius's formula,

pH = -log[H+]

⇒9.5 = -log[H+]

⇒[H+] = antilog(-9.5) ≈ 3.1 × 10^-10

hence, concentration of hydrogen ion is 3.1 × 10^-10