A sealed industrial chamber contains an equilibrium mixture for the reaction P(g)+Q(g)⇌R(g)\mathrm{P(g) + Q(g) \rightleftharpoons R(g)}P(g)+Q(g)⇌R(g). More R\mathrm{R}R is introduced into the chamber.
Which statement correctly describes the result?
The position shifts towards P and Q, so more P and Q form.
The position shifts towards R, so more R forms.
The position stays unchanged because adding R only changes its amount.
The direction cannot be predicted without the original amounts of P, Q and R.
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.