Substances P and Q react together to form substance T. A student wants evidence that this reaction is reversible.
Which observation gives this evidence?
The mass of T formed equals the mass of P and Q used.
The mixture of P and Q gets hot as T is formed.
P and Q form T more quickly when the mixture is warmed.
Heating T produces P and Q, which form T again on cooling.
124 exam-style questions on OCR GCSE Chemistry 5.3 Equilibria, covering 5.3.1 Reversible reactions and dynamic equilibrium and 5.3.2 Changing the position of equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.