Energy changes in chemical reactions

Exothermic and endothermic reactions, activation energy and simple energy profile diagrams.

1st Year2nd Year3rd Year Common

Helps to know first: Chemical reactions and conservation of mass

15practice questions

Match the pairs: 2 · Multiple choice: 7 · Select all that apply: 1 · Numeric answer: 3 · Short answer: 1 · Written answer (self/teacher assessed): 1

Each question has up to three hints, a worked explanation, and is tracked in your progress and review plan.

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Read the passage: Investigation: temperature changes in reactions

A student mixed pairs of solutions in a polystyrene cup and recorded the starting and highest or lowest temperature for three reactions. Reaction | Starting temperature (°C) | Final temperature (°C) A: magnesium + hydrochloric acid | 19 | 34 B: citric acid + sodium hydrogencarbonate | 19 | 11 C: sodium hydroxide + hydrochloric acid | 19 | 26

Numeric answerExam-style long question (Section B style)