Hydrogen burns in oxygen in an exothermic reaction. Four positions on the reaction profile are described.
| Position | Location on the reaction profile |
|---|---|
| P | Reactant energy level |
| Q | Highest point of the reaction pathway |
| R | Product energy level |
| S | Bottom of the vertical energy axis |
What does an arrow showing the overall energy change connect?
The highest point at Q and the product energy level at R
The highest point at Q and the bottom of the energy axis at S
The reactant energy level at P and the highest point at Q
The reactant energy level at P and the product energy level at R
85 exam-style questions on AQA GCSE Chemistry 5.1 Exothermic and endothermic reactions, covering 5.1.1 Energy transfer during exothermic and endothermic reactions, 5.1.2 Reaction profiles, and 5.1.3 The energy change of reactions. Each one has a worked solution and a mark scheme showing where the marks go.