An agricultural scientist mixes four soil samples separately with distilled water. The scientist tests each clear liquid extract using universal indicator paper.
| Soil extract | Colour shown by universal indicator paper |
|---|---|
| J | orange |
| K | green |
| L | blue |
| M | yellow |
Which conclusion about the extracts is correct?
Extract L has a lower pH than extract K.
Extract K is alkaline.
Extract J is neutral.
Extract M is acidic.
112 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.