A technician makes four acid solutions, A, B, C and D.
The table shows information about the solutions.
| Solution | Acid | Concentration of acid (mol/dm³) | pH |
|---|---|---|---|
| A | hydrochloric acid | 1.0 | 0 |
| B | hydrochloric acid | 0.10 | 1 |
| C | ethanoic acid | 1.0 | 2 |
| D | ethanoic acid | 0.10 | 3 |
Which solution has the highest concentration of hydrogen ions?
Solutions A and C have the same concentration of acid but different pH values.
Explain why. Use ideas about ionisation.
Explain what is meant by a dilute acid. Use solutions C and D in your answer.
The technician wants to make a solution of hydrochloric acid with the same pH as solution D.
Calculate the concentration of hydrochloric acid that the technician should use.
53 exam-style questions on OCR GCSE Chemistry 3.3 Types of chemical reactions, covering 3.3.1 Oxidation and reduction in terms of oxygen, 3.3.2 Acids, alkalis and neutralisation, 3.3.3 The pH scale and measuring pH, 3.3.4 Oxidation and reduction in terms of electrons, 3.3.5 Dilute and concentrated, weak and strong acids, and 3.3.6 Hydrogen ion concentration and pH. Each one has a worked solution and a mark scheme showing where the marks go.