Using the figure below, which of the following best describes the titration curve?
A) The equivalence point for the titration is pH = 7.
B) The midpoint of the titration is pH = 7.
C) The pKa for this weak acid is 4.76.
D) This is a titration of a weak base by NaOH.

Question

Using the figure below, which of the following best describes the titration curve? 
A) The equivalence point for the titration is pH = 7. 
B) The midpoint of the titration is pH = 7. 
C) The pKa for this weak acid is 4.76. 
D) This is a titration of a weak base by NaOH.

Quizplus · Accepted Answer

The curve shows a typical titration of a weak acid with a strong base. The equivalence point is above pH 7, indicating that the conjugate base of the acid is being formed. The midpoint of the titration (halfway to the equivalence point) is at a pH slightly below 7, indicating that the acid is only partially neutralized at this point. The pKa of the acid can be determined from the vertical portion of the curve (the buffer region), where the pH changes only slightly with the addition of more base. The pKa for this weak acid is approximately 4.76.

Using the Figure Below, Which of the Following Best Describes