Many chemical reactions can be reversed.
When this happens we can describe a forward reaction and a back reaction.
Sometimes the forward and back reaction take place at equal rates. When this happens an Equilibrium is established
Students should:
- 3.17 know that some reactions are reversible and this is indicated by the symbol ⇌ in equations
Reversible reactions
Students should:
- 3.18 describe reversible reactions such as the dehydration of hydrated copper(II) sulfate and the effect of heat on ammonium chloride
This classic demonstration is used to demonstrate diffusion rates
In this video you can see the same process happening in close up. Hydrogen chloride is combining with ammonia gas to make the white solid called ammonium chloride.
Dynamic equilibria
This video shows and describes the principles of dynamic equilibrium. These are:
- reversible chemical reactions are only in equilibrium if: the temperature is constant and the reaction is taking place in a closed system.
- a closed system cannot exchange matter with its surrounding but can exchange energy.