What this tests
Syllabus point 5.1 — Exothermic and endothermic reactions, in Chemical energetics. Difficulty medium (estimated from the question's demands, not a Cambridge rating).
Cambridge IGCSE Chemistry 0620 · 5.1 Exothermic and endothermic reactions
November 2014 · Paper 13 · Question 13
One real Cambridge question from Chemical energetics, with the official answer.