Shift to reactants(left)
<h3>Further explanation
</h3>
A buffer solution is a solution that can maintain a good pH value due to the addition of a little acid or a little base or dilution.
The buffer solution can be acidic or basic
Acid buffer solutions consist of weak acids and their salts.
A buffer solution of NaC2H202 and HC2H2O2 (acetic acid) is included in the acid buffer
So :
a slight addition of acid (H⁺) will be balanced by the conjugate base
the addition of a small base (OH⁻) will be balanced by the weak acid
With the addition of acid (H +), the equilibrium will shift to the left, in the formation of CH3COOH. The added acid will be neutralized by the conjugate base component (CH3COO−).