Final answer:
A buffer is a solution that resists changes in pH when small amounts of acid or base are added. In the case of the HC2H3O2/NaC2H3O2 buffer, if HClO4(aq) is added, it will react with the HC2H3O2 in an acid-base reaction. Instead of drastically changing the pH by making the solution more acidic, the added acid reacts with the weak acid in the buffer to form its conjugate base, resulting in a minimal change in pH.
Step-by-step explanation:
A buffer is a solution that resists changes in pH when small amounts of acid or base are added. In the case of the HC2H3O2/NaC2H3O2 buffer, if HClO4(aq) is added, it will react with the HC2H3O2 in an acid-base reaction:
HClO4(aq) + HC2H3O2(aq) → H2O(l) + C2H3O2-(aq)
Instead of drastically changing the pH by making the solution more acidic, the added acid reacts with the weak acid in the buffer to form its conjugate base, resulting in a minimal change in pH.