Which description best matches the typical titration curve of a weak acid titrated with a strong base?

• A. The curve shows a continuous, linear increase in pH.
• B. The curve shows a buffer region, a steep rise near equivalence, and a final pH above 7.
• C. The curve has a buffer region but no steep rise.
• D. The curve ends with pH exactly 7.

Answer: (B)

When a weak acid is titrated with a strong base, the curve shows a buffering region where the weak acid and its conjugate base neutralize added base, followed by a sharp rise in pH as you approach the equivalence point, and after that point the solution contains mostly the conjugate base, making the pH rise above 7. This pattern matches the description of a buffer region, a steep increase near equivalence, and a final pH above 7, which is why that option is the best fit.

The other descriptions don’t fit the situation: a linear, continuous pH increase ignores buffering behavior and the sharp change near equivalence; having a buffer region but no steep rise misses the rapid pH change at the equivalence point; ending at pH exactly 7 would imply a neutral equivalence point, which isn’t the case for a weak acid titrated with a strong base.