Question

Which equations explain how a solution of CH3COOH and CH3COOK act as a buffer solution when small amount of
1. H2SO4 is added
2. KOH is added

Answer 1

1. When a small amount of H2SO4 is added to a solution of CH3COOH and CH3COOK, the following equilibrium reactions occur:

CH3COOH + H2O ⇌ CH3COO- + H3O+
CH3COO- + H2O ⇌ CH3COOH + OH-

The addition of H2SO4 will react with the CH3COO- ions to form CH3COOH, maintaining the concentration of the weak acid in the solution. This will prevent a drastic change in pH, making the solution act as a buffer.

2. When a small amount of KOH is added to a solution of CH3COOH and CH3COOK, the following equilibrium reactions occur:

CH3COOH + OH- ⇌ CH3COO- + H2O
CH3COO- + H2O ⇌ CH3COOH + OH-

The addition of KOH will react with the CH3COOH molecules to form CH3COO- ions, maintaining the concentration of the weak base in the solution. This will prevent a drastic change in pH, making the solution act as a buffer.