Calculate Kb for a 0.1 M solution of cyanide ion, given that Ka for hydrocyanic acid is 6.2 x 10â10.a) 8.4 x 10â9b) 7.87 x 10â3c) 1.34 x 10â3d) 1.8 x 105e) 7.87 x 10â6f) 1.61 x 10â5g) 7.4 x 10â8

Kb = 1.6 × 10⁻⁵

Explanation:

Step 1: Given data

Acid dissociation constant of hydrocyanic acid (Ka): 6.2 × 10⁻¹⁰

Concentration of cyanide ion (Cb): 0.1 M

Step 2: Calculate the basic dissociation constant (Kb) of cyanide ion

We have the Ka of HCN. We can calculate the Kb of its conjugate base using the following expression.

Ka × Kb = Kw = 1.0 × 10⁻¹⁴

Kb = 1.0 × 10⁻¹⁴/Ka

Kb = 1.0 × 10⁻¹⁴/6.2 × 10⁻¹⁰

Kb = 1.6 × 10⁻⁵