Question

Calculate degree of hydrolysis and ph of 0.01m of kcn . Ka of hcn is 4×10 power 10

Answer 1

Answer:

If pKa =4, Ka = 1E-4

As it's a weak acid we can assume that the concentration of hydrogen ions equals the concentration of cyanide ions.

So using the Ka expression for HCN, the concentration of hydrogen ions = √(0.01 × 1E-4) = 0.001 mol/dm³

Hence

pH = -log(0.001) = 3