An analytical chemist measures the melting point of three different recrystallised batches of benzoic acid, labelled A, B, and C. The measured melting point data is recorded in the table below.
| Batch | Melting point / °C |
|---|---|
| A | 112–117 |
| B | 122 |
| C | 115–119 |
Determine whether each batch is pure or impure, and justify your conclusions using the information provided.
107 exam-style questions on Edexcel GCSE Chemistry 3.2 Methods of separating and purifying substances, covering 3.2.1 Pure substances and mixtures, 3.2.2 Techniques for separating mixtures, 3.2.3 Paper chromatography and Rf values, and 3.2.4 Making water potable. Each one has a worked solution and a mark scheme showing where the marks go.