Cambridge IGCSE Chemistry · Syllabus 0620 · Chemical Reactions
Position of Equilibrium
What is Position of Equilibrium?
A description of how far a reversible reaction has proceeded when equilibrium is reached, in other words the relative amounts of reactants and products in the equilibrium mixture. It moves to the right when more product is present at equilibrium and to the left when more reactant is, and it is changed by temperature, pressure and concentration but never by a catalyst.
This definition is part of the Chemical Reactions chapter in Cambridge IGCSE Chemistry.
Common mistakes with Position of Equilibrium
- 16. “Heat acts as a catalyst.” Supplement 6.3.4 Why temptingBoth speed reactions up. RepairA catalyst lowers \(E_\mathrm{a}\) and leaves the position of equilibrium alone. Heat leaves \(E_\mathrm{a}\) alone and does move the position. They are opposites in both respects. TransferWhich of the two changes the yield? Heat.
Examiner tips on Position of Equilibrium
- The row worth memorising is the third. Whenever the gas counts are equal, the correct answer to “what happens to the position of equilibrium?” is nothing. Students who have learned “pressure pushes it right” as a slogan get this wrong every time. Pressure still speeds the reaction up — but it does not move the position.