ACIDS and BASES

1 / 29

For the reaction described by the following equations:

NH₄⁺ + OH^- => NH₃ + H₂O

Which one of the following statements is correct?
1. NH₄⁺ is behaving as a base
2. NH₄⁺ is behaving as an acid
3. NH₄⁺ is oxidised
4. NH₄⁺ is reduced
What is the concentration of a Ba(OH)₂ solution that has a pH of 9.30?
1. 2.00 x 10^-5 mol L^-1
2. 1.00 x 10^-5 mol L^-1
3. 2.50 x 10^-10 mol L^-1
4. 5.01 x 10^-10 mol L^-1
The pH of 0.050 mol L^-1 solution of hydrogen cyanide is 6.40. What percentage of the hydrogen cyanide in this solution has ionised?
1. 4.0 x 10^-7 %
2. 4.0 x 10^-5 %
3. 8.0 x 10^-4 %
4. 8.0 x 10^-6 %
When asked to list the properties of an acid-base indicator a student gave four statements (A-D).

A It must undergo an acid-base reaction

B It is easily oxidised to a coloured product

C It has acid-base conjugate forms with different colours

D It can be used to prepare a standard solution

The student`s response was not entirely correct, as only some of the statements were true. Which combination of statements is correct?
1. Only A and D
2. Only A and B
3. Only A and C
4. Only B and C
Sulfuric acid is a stronger acid than acetic (ethanoic) acid. Which one of the following statements best explains this?
1. Sulfuric acid ionises to a geater extent than acetic acid
2. Sulfuric acid has two hydrogen atoms available for ionisation per molecule, while acetic acid has only one hydrogen atom available for ionisation per molecule
3. Sulfuric acid is more soluble in water than acetic acid
4. Concentrated sulfuric acid has a concentration of 18 mol L^-1, while concentrated acetic acid has a concentration oof 17 mol L^-1
Which one of the following equations does not represent the donation and acceptance of protons?
1. H₂O₂ + OH- <=> HO₂^- + H₂O
2. H₂C₂O₄ + CO₃^2- <=> HC₂O₄^-- + HCO₃^-
3. H⁺ + OH^- <=> H₂O
4. 2 H⁺ + 2 e^- <=> H₂
For the following equation

H₂SO₃ + H₂O₂ => H₂SO₄ + H₂O

which one of the following statements is true?
1. Hydrogen Peroxide is actings as an acid
2. Hydrogen Peroxide is acting as an oxidising agent only
3. Hydrogen Peroxide is actings as an acid and a base
4. Hydrogen peroxide is acting as an oxidising and reducing agent
In which one of the following will each listed compound dissolve in water to give a basic solution?
1. ammonia, sodium oxide, potassium carbonate, barium hydroxide
2. potassium acetate, sodium carbonate, ammonia, ammonium chloride
3. sodium sulfate, potassium chloride, magnesium oxide, aluminium oxide
4. carbon dioxide, sodium chloride, potassium hydroxide, ammonia
What is the pH of a 5.0 x 10^-3 mol L^-1 solution of barium hydroxide?
1. 12
2. 11.7
3. 2
4. 2.3
The water in a seriously neglected swimming pool is tested and found to have a pH of 3. By what factor must the hydrogen ion concentration be changed to increase the water pH to 6?
1. increase the hydrogen ion concentration by 1000 times
2. decrease the hydrogen ion concentration by 1000 times
3. halve the hydrogen ion concentration
4. double the hydrogen ion concentration
A chemist measures the pH of four 1.0 x 10^-2 mol L^-1 acid solutions, and obtains the following results.

Experiment Solution pH
1 1.0 x 10^-2M CH₃COOH 3.4
2 1.0 x 10^-2M H₃PO₄ 2.2
3 1.0 x 10^-2M HNO₃ 2.0
4 1.0 x 10^-2M H₂SO₄ 1.4

Which experimental result must be incorrect?
1. experiment 2
2. experiment 1
3. experiment 3
4. experiment 4
Consider the following three statements (I-III) about neutralisation reactions.

I A neutralisation reaction is a reaction between an acid and a base
II At the equivalence point of a neutralisation reaction the pH of the resulting solution will be 7
III Salts are obtained from neutralisation reactions

Which statement or combination of statements is always correct?
1. Only I
2. Only I and II
3. I, II and III
4. Only I and III
Each of the following salts is dissolved in water. Which answer correctly classifies the salts as acidic , basic or neutral?

Na₂CO₃ (aq) ; NH₄Cl(aq) ; K₃PO₄(aq) ; FeCl₃(aq)
1. basic, acidic, basic, acidic
2. neutral, acidic, basic, basic
3. basic, basic, acidic, acidic
4. acidic, basic, neutral, basic
20.0 mL of a 0.0100 mol L^-1 solution of NaOH is added to 20.0 mL of a 0.0300 mol L^-1 solution of NaCl. What is the pH of the resulting solution?
1. 11.70
2. 2.00
3. 12.00
4. 7.00
Which one of the following correctly identifies the acidity, basicity or neutrality of each of the given solutions?

sodium hydrogensulphate potassium phosphate ammonium chloride magnesium nitrate
1. acidic, basic, acidic, neutral
2. acidic, acidic, acidic, basic
3. basic, neutral, basic, neutral
4. neutral, basic, neutral, acidic
What is the pH of 0.0050 mol L^-1 solution of Ba(OH)₂?
1. 2.00
2. 12.00
3. 2.30
4. 11.70
A chemist carries out a titration and records the following values in the report book.

Final reading (mL) 11.6 22.00 32.41 42.07 11.47
Initial reading (mL) 0.20 11.60 22.00 32.41 1.05

What titration value should the chemist use in a subsequent calculation?
1. 10.46
2. 10.41
3. none of these
4. 10.22
Household vinegar can be produced by adding 250 mL of glacial (nearly pure) acetic (ethanoic) acid to 10 L of pure water. Which one of the following best describes the glacial acetic acid?
1. a concentrated solution of a weak acid
2. a dilute solution of a strong acid
3. a concentrated solution of a strong acid
4. a dilute solution of a weak acid
Which one of the following statements about 1.00 x 10^-8 mol L^-1 HCl is correct?
1. The pH is a little less than 7
2. The pH is 6
3. The pH is 8
4. Such a solution cannot exist
When the pH of a 0.01 mol L^-1 solution of sulfuric acid is measured it is found to be significantly lower than the pH of a 0.01 mol L^-1 solution of phosphoric acid. What is the reason for this?
1. Phosphoric acid is a stronger acid than the sulfuric acid, so the phosphoric acid is more likely to produce hydrogen ions in solution than sulfuric acid
2. Phosphoric acid is a triprotic acid, while sulfuric acid is only diprotic, therefore the concentration of hydrogen ions is higher in the phosphoric acid solution than in the sulfuric acid solution
3. The sulfuric acid solution is more concentrated than the phosphoric acid soltuion, therefore there will be more hydrogen ions in the sulfuric acid solution than the phosphoric acid solution.
4. Sulfuric acid is a much stronger acid than phosphoric acid, so there are more hydrogen ions in the sulfuric acid solutions than the phosphoric acid solution
Which one of the following species cannot act as both a Bronsted-Lowry acid and base?
1. NH₃
2. HCO₃^-
3. CH₄
4. HSO₄^-
Which one of the following correctly defines an acid according to the Bronsted-Lowry theory?
1. forms H⁺ions in water
2. accepts H⁺ions in water
3. H⁺ donor
4. H⁺ acceptor
Pure water undergoes self-ionisation according to the equation.

2H₂O (l) => H₃O⁺(aq) + OH^-(aq)

The equilibrium constant for the reactrion is:

1.0 x 10^-14 at 25^oC and 5.5 x 10^-13 at 100^oC

Which one of the following statements is correct?
1. At 100^oC the pure water is obviously still neutral and the pH must be 7.0
2. At 100^oC the pH of pure water is greater than 7.0, and therefore the water is basic
3. At 100^oC the pH of pure water is less than 7.0, but the water is still neutral
4. At 100^oC the pH of pure water is less than 7.0, and therefore the water is acidic
Which one of the following is most likely to be able to act as both an acid and a base?
1. Cl^-
2. O^2--
3. OH^-
4. NH4⁺
Which of the following statements best describes a neutral aqueous solution?
1. The solution contains no basic or acidic species
2. The pH is 7
3. The solution may contain dissolved salts
4. The concentration of H⁺ and OH^- are equal
Which one of the following equations does not represent the donation and aceptance of protons?
1. NH₃ + OH^- <=> NH_2- + H₂O
2. Zn + 2 H⁺ <=> Zn²⁺ + H₂
3. HOCl + C₆H₅COO- <=> OCl^- + C₆H⁵COOH
4. C₆H⁵COOH + HCO3_-^-<=> C₆H₅COO- +H₂CO₃
Ammonia is classified as a weak electrolyte. Which of the following statements best explains this?
1. In a water-solution only some of the ammonia molecules have reacted with water molecules
2. Hydrogen bonding exists between ammonia molecules
3. Ammonia is very soluble in water
4. A water solution of ammonia contains more hydroxide ions than hydrogen ions
Solid sodium acetate is added to water. Which one of the following statements best describes what happens?
1. The pH increases because the sodium ions react with water to produce hydroxide ions
2. The pH decreases because the sodium ions react with water to produce hydrogen ions
3. The pH decreases because the acetate ions react with water to produce acetic acid
4. The pH increases because the acetate ions react with water to produce hydroxide ions
Which one of the following groups contains only oxides that would form acids when dissolved in water?
1. NO₂, SO₂, Cl₂O
2. NO₂, Na₂O,CO₂
3. MgO, CaO,Al₂O₃
4. MgO, Cl₂O, PbO

Experiment	Solution	pH
1	1.0 x 10^-2M CH₃COOH	3.4
2	1.0 x 10^-2M H₃PO₄	2.2
3	1.0 x 10^-2M HNO₃	2.0
4	1.0 x 10^-2M H₂SO₄	1.4

Final reading (mL)	11.6	22.00	32.41	42.07	11.47
Initial reading (mL)	0.20	11.60	22.00	32.41	1.05

ACIDS and BASES

Multiple Choice Quiz on Acids and Bases