Given : pH=5.74 Concentration of acetic acid in buffer =1.0M Acetic acid and its conjugate base sodium acetate makes acidic buffer. CH3COOH+CH3COONa⟶ (Acidic buffer) Using formula, pH=pKa+log
[ Salt ]
[ Acid ]
pH=pK+agg
[CH3COONa]
[CH3COOH]
5.74=4.74+log
[CH3COONa]
[CH3COOH]
5.74−4.74=log
[CH3COONa]
[CH3COOH]
1=log
[CH3COONa]
[CH3COOH]
⇒
[CH3COONa]
[CH3COOH]
=10[∴[CH3COOH]=1] [CH3COONa]=[10×1]=10 Thus, the concentration of sodium acetate in buffer is 10M.