A weak acid HA is being titrated with NaOH. The boxed region of the curve is shown.
Why is pH nearly flat in the boxed region?
- A
All HA has reacted
- B
OH- is in large excess
- C
Water self-ionization dominates
- Dcheck_circle
A buffer of HA / A- resists pH change
Explanation
Between the start and the equivalence point, the solution contains comparable amounts of HA and A-, forming a buffer that resists pH change.