This deep dive covers Deep Dive: Dynamic Equilibrium within Equilibrium (HT) for GCSE Chemistry. Revise Equilibrium (HT) in Rates of Reaction for GCSE Chemistry with 20 exam-style questions and 15 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 3 of 14 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 3 of 14
Practice
20 questions
Recall
15 flashcards
🔬 Deep Dive: Dynamic Equilibrium
A reversible reaction is one that can go in both directions — products can turn back into reactants. The symbol ⇌ (two half-arrows pointing in opposite directions) is used to show this. You will see it in equations such as N₂ + 3H₂ ⇌ 2NH₃, meaning the reaction can proceed both left-to-right and right-to-left. (If you have studied Topic 35 Reversible Reactions, this notation is already familiar.)
At equilibrium:
Rate of forward reaction = Rate of backward reaction
Why are concentrations constant at equilibrium? Both reactions are happening at the same speed, so every molecule of product being made is balanced by one being destroyed. The net result is no overall change — like filling a bath with the plug out, where water flows in at the same rate it drains. The level stays constant not because nothing is happening, but because two opposing processes are perfectly balanced.
Key features of equilibrium:
- Dynamic — reactions are still happening in both directions
- Closed system — nothing can enter or leave
- Concentrations are constant — but not necessarily equal
- Position can be changed — by altering conditions