AP®ChemistryCollege BoardExam QuestionsUnit 8: Acids & BasesAcid-Base Titrations

Acid-Base Titrations (College Board AP® Chemistry): Exam Questions

1 hour22 questions

Select a download format for Acid-Base Titrations

Scroll for more

Select an answer set to view for
Acid-Base Titrations

Easy
Medium
Hard
11 mark
PH curve

Which type of titration is indicated by the pH curve above?

  • Strong acid - strong base

  • Weak acid - weak base

  • Strong acid - weak base

  • Weak acid - strong base

Choose your answer

21 mark

The table below shows the pKa values of four acid-base indicators:

Indicator

pKa

Methyl orange

3.7

Phenolphthalein

9.6

Phenol red

7.9

Bromothymol blue

7.0

Which indicator would be most appropriate for a titration between hydrochloric acid and ammonia?

  • Methyl orange

  • Phenolphthalein

  • Phenol red

  • Bromothymol blue

Choose your answer

11 mark

A 0.10 mol dm-3 solution of propanoic acid is titrated with 0.10 mol dm-3 potassium hydroxide.

Which of the following statements accurately describes this titration

  • The equivalence point occurs at pH 7.

  • The salt formed hydrolyzes to form an acidic salt.

  • The salt formed at the equivalence point is CH3COOK.

  • At the half-equivalence point, [CH3CH2COOH] = [CH3CH2COO-].

Choose your answer

21 mark

During a titration, 23.70 cm3 of 0.02 mol dm-3 potassium hydroxide (KOH) is used to completely neutralize 0.03 mol dm-3 sulfuric acid (H2SO4).

What is the required volume of H2SO4 solution to reach the equivalence point?

  • 7.90 cm3

  • 31.65 cm3

  • 15.80 cm3

  • 17.78 cm3

Choose your answer

31 mark

In a titration, the equivalence point is reached when 23.70 mL of 0.02 M potassium hydroxide reacts with 0.03 M of sulfuric acid. What volume of acid is needed?

  • 7.9 mL

  • 31.65 mL

  • 15.80 mL

  • 17.78 mL

Choose your answer

41 mark

The acid–base indicator bromophenol blue changes colour from yellow to blue over a pH range of 3.0–4.6. Which statement(s) is/are correct?

I. The pKa is between 3.0 and 4.6

II. In a neutral solution [HIn] > [In-]

III. It is a suitable indicator for a strong acid, weak base titration

  • I and II only

  • I and III only

  • II and III only

  • I, II and III

Choose your answer

11 mark
5-6-chem--q3


The pH curve above represents a weak acid, strong base titration. The pH of the acid at half equivalence point is 4.90.

What is the Ka of the acid?

  • 4.90

  • 8.72

  • 1.26 x 10-5

  • 1.91 x 10-9

Choose your answer

21 mark

A titration is carried out using 25.00 cm3 of 0.100 mol dm-3 propanoic acid and 0.100 mol dm-3 sodium hydroxide. Phenolphthalein (pH range: 8.3 – 10.0) is used to determine the equivalence point.

If 0.100 mol dm-3 hydrochloric acid is used instead of propanoic acid, which of the following remains unchanged?

  • The volume of base required to reach the equivalence point.

  • The pH at the equivalence point.

  • The y-intercept of the pH curve.

  • The color of the solution just before equivalence is reached.

Choose your answer

31 mark

The pKb value of HPO42- is 6.8.

What is its conjugate acid and what is the Ka value?

  • H2PO4-, 7.2

  • H3PO4, 7.2

  • H3PO4, 1.67 x 10-7

  • H2PO4-, 6.3 x 10-8

Choose your answer

41 mark

Which of the following salts would produce a solution with the highest pH if dissolved in water?

  • RbCl

  • CuSO4

  • KCl

  • Na2CO3

Choose your answer

51 mark

The table below shows data for the and values for some acids and bases at 298 K.

Acid

Ka

Base

pKb

C5H6OH

1.02 x 10-10

(C2H5)3N

3.25

O2NC6H4OH

7.08 x 10-8

C6H5NH2

9.13

Which two formulas represent the weakest acid and the weakest base in the table?

  • C5H6OH and C6H5NH2

  • O2NC6H4OH and C6H5NH2

  • O2NC6H4OH and (C2H5)3N

  • C5H6OH and (C2H5)3N

Choose your answer