Below are some examples of chemical reactions.
In this reaction you will see that magnesium reacts quickly to produce bubbles of hydrogen gas.
Heat is given off in this reaction, it is an example of an exothermic reaction.
This reaction is not as fast as the reaction between magnesium and hydrochloric acid and produces an insoluble solid known as a precipitate.
This makes the mixture appear cloudy (so you can no longer see through it).
This reaction has been speeded up in the video and the complete reaction will take at least 24 hours to complete.
It is an example of a slow reaction as the bubbles of (carbon dioxide, CO₂) gas produced in the reaction form very slowly.
The reaction speed or RATE can be measured as the 'rate of formation of product' or the 'rate of disappearance of a reactant'