10-minute Quiz : Chapter 16 Indicators and pH

The following table shows the pH of three solutions, X, Y and Z. A few drops of methyl orange are added to each solution. Which of the following combinations about the colour of methyl orange in these solutions is correct?

• A

• B

• C

• D

A sample of hydrochloric acid has a pH of 0.5. What is the concentration, in g dm⁻³, of the sample of the acid?

(Relative atomic masses: H = 1.0, Cl = 35.5)

• A. 0.00866

• B. 0.316

• C. 11.5

• D. 18.3

Which of the following substances has the highest pH?

• A. Yoghurt

• B. Tea

• C. 0.05 M nitric acid

• D. Baking soda solution

A student carried out two tests on solutions M and N respectively. The table below shows the results of the two tests. Which of the following combinations about the pH of these solutions is correct?

• A

• B

• C

• D

Which of the following acids have a pH of 2.0?

(1) 0.020 M HNO₃(aq)

(2) 0.010 M HCl(aq)

(3) 0.0050 M H₂SO₄(aq)

• A. (1) and (2) only

• B. (1) and (3) only

• C. (2) and (3) only

• D. (1), (2) and (3)

The table below shows the colour of thymol blue, an acid-base indicator, over different pH ranges. Which of the following combinations about the colour of thymol blue in 0.5 M HCl(aq) and oven cleaner respectively is correct?

• A

• B

• C

• D

A sample of an acid has a pH of 2.8. 50 cm³ of the sample of the acid is diluted to 200 cm³ by adding distilled water. What is the pH of the diluted sample?

• A. 0.7

• B. 3.4

• C. 5.6

• D. 6.8

A piece of red litmus paper is dipped into an unknown solution and it remains red. Which of the following additional steps could be carried out to confirm that the solution is acidic?

• A. Observing whether the solution is clear

• B. Tasting the solution

• C. Measuring the electrical conductivity of the solution

• D. Testing the solution with a piece of blue litmus paper

500 cm³ of a sample of sulphuric acid has a pH of 1.5. What is the mass of sulphuric acid in the sample?

(Relative atomic masses: H = 1.0, O = 16.0, S = 32.1)

• A. 0.39 g

• B. 0.78 g

• C. 0.96 g

• D. 1.6 g

A sample of hydrochloric acid has a pH of 2.0. 50 cm³ of this sample is mixed with 100 cm³ of sodium chloride solution. What is the pH of the resultant mixture?

• A. 0.7

• B. 2.0

• C. 2.5

• D. 2.9