IB Chemistry 1-2

Acid Base Practice Test

1. Which of the following properties is true of acids?

A. They change blue litmus paper to redB. They change phenolphthalein from a reddish pink color to colorlessC. They have a sour tasteD. All of these are true

2. Carbon dioxide gas can be distinguished from other gases because it

A. it explodes when exposed to a burning splintB. it turns bromthymol blue solution yellowC. it turns limewater milkyD. both B and C are correct

3. According to the G.N. Lewis definition an acid is a(n)

A. Proton donorB. Proton acceptor C. Electron donorD. Electron acceptor

4. According to the Bronsted Lowry definition a base is a(n)

A. Proton donorB. Proton acceptorC. Electron donorD. Electron acceptor

5. Which of the following compounds can never act as a Bronsted-Lowry acid?

A. H2OB. HClO C. NH2

-

D. Br-.

6. A substance that can act as either an acid or a base is

A. amphotericB. neutral C. a conjugate baseD. a conjugate acid

7. The pH of solution X is 1 and that of Y is 2. Which statement is correct about the hydrogen ion concentrations in the two solutions?

A. [H+] in X is half that in YB. [H+] in X is twice that in YC. [H+] in X is one tenth of that in YD. [H+] in X is ten times that in Y

8. Which pair of substances can be used to prepare a buffer solution?

A. a strong acid and one of its corresponding soluble salts.B. a weak acid and one of its corresponding soluble salts.C. a strong acid and a weak base.D. a weak acid and a strong base.

9. Compared to strong acids, weak acids are

A. less soluble than strong acidsB. less concentrated than strong acidsC. less polar than strong acidsD. less ionized in water solution

10. In the titration curve below

A. Curve 1 is a strong acid and curve II is a weak acid; both neutralized by a strong baseB. Curve 1 is a weak acid and curve II is a strong acid; both neutralized by a weak baseC. Curve 1 is a strong acid and curve II is a weak acid both neutralized by a weak baseD. Curve 1 is a weak base and curve II is a strong base both neutralized by a acid baseE. None of the above

11. The following values represent the pKb values for some common weak bases. Of these bases which one is the strongest?

A. 10.0B. 8.0C. 6.5D. 5.0

12. Which of the following is an example of a neutral salt?

A. KCH3COOB. NaClC. CsOHD. AlCl3

13. What is the pH of 1.0 x 10-2 M solution of HCN? (For HCN, Ka = 4.0 x 10-10)

A. 4 or belowB. Between 4 and 7C. Between 7 and 10D. 10 or above

14. The following table shows the pH ranges for three common acid base indicators:

Acid Color Range Base color

Phenolphthalein Colorless 8.3-10.8 redBromothymol blue

Yellow 6.0-7.6 blue

Methyl orange red 3.1-4.4 yellow

A certain solution is colorless in phenolphthalein, yellow in bromothymol blue and yellow in methyl orange. What is the approximate pH of the solution?

A. Between 3 and 4B. Between 4 and 6C. Between 6 and 7.5D. Between 7.5 and 8.5

15. Use the Henderson-Hasselbach equation calculate the pH of a solution that is 0.100 M in CH3COOH and

0.200 M CH3COO- The Ka for CH3COO-

is 1.8x 10-5.

A. 0.30B. 4.45C. 4.75D. 5.05

16. Which of these is true about a buffered solution?

I. The pH is always higher than the non-buffered solutionII. The pH is always equal to the pKa value for the acid

A. I onlyB. II onlyC. Both I and IID. Neither I nor II

17. Calculate the concentration of a hydrochloric acid solution if 40 cm3 of it exactly neutralizes 50 cm3 of a 0.05 M BaOH)2 solution

2 HCl + Ba(OH)2 à BaCl2 + 2 H2O

18. Calculate the [H3O+] concentration and the pH of a solution of 0.20 butanoic acid, HC4H7O2 solution?.

The Ka for butanoic acid 1.52 x 10-5

19. Calculate the [H3O+] concentration and the pH of a buffer solution that is 0.20 M butanoic acid, and 4.0

M sodium butanoate, NaC4H7O2 The ka for butanoic acid 1.52 x 10-5

Answers

1. D

2. D

3. D

4. B

5. D

6. A

7. D It has no hydrogens to donate

8. B

9. D

10. E None of the above. Curve 1 is a weak acid and Curve II is a strong acid. Both neutralized by a strong base

11 D Just like Ka the smaller the Kb the stronger the base

12. B

13. B

14 B

15. D

16. D

17 0.125 M note that there are 2 moles of acid to 1 mole of base the mole factor is ½

18 [H3O+] = 1.73 x 10-3, pH = 2.76

19 note that the base is 20 times more concentrated. pH = 6.2