The table shows the pH of four acid solutions at 25 ∘C25\,^\circ\mathrm{C}25∘C.
| Solution | Acid | Concentration in mol dm−3\mathrm{mol\,dm^{-3}}moldm−3 | pH |
|---|---|---|---|
| P | hydrochloric acid | 0.10 | 1.0 |
| Q | ethanoic acid | 0.10 | 2.9 |
| R | ethanoic acid | 1.0 | 2.4 |
| S | hydrochloric acid | 0.0010 | 3.0 |
Statement 1: R is more concentrated than P, but the acid in P is stronger
Statement 2: S has a higher pH than Q, so hydrochloric acid is a weaker acid than ethanoic acid
Statement 3: in Q, most of the ethanoic acid molecules have not dissociated into ions Which statements are correct?
1 only
1 and 3 only
2 and 3 only
1, 2 and 3
44 exam-style questions on Edexcel GCSE Chemistry 4.1 Acids, covering 4.1.1 Acids, alkalis and the pH scale, 4.1.2 Hydrogen ion concentration and pH, 4.1.3 Dilute and concentrated, weak and strong acids, 4.1.4 Bases, alkalis and the reactions of acids, 4.1.5 Chemical tests for hydrogen and carbon dioxide, 4.1.6 Neutralisation as a reaction of acids with bases, 4.1.7 Preparing soluble salts, and 4.1.8 Solubility rules and preparing insoluble salts. Each one has a worked solution and a mark scheme showing where the marks go.