Oxygen was discovered in the eighteenth century by the English scientist Joseph Priestley.
Priestley carried out investigations using a bell jar. He discovered that a plant can survive in a sealed jar. He then investigated how this would apply to animals and found that a mouse placed inside a sealed jar will eventually collapse. However, he discovered that a mouse in a sealed jar with a plant will survive as the plant restores oxygen in the air.
Priestley was the first to show that oxygen is needed for animals to survive but that, given time, plants create oxygen, allowing animals to breathe.
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Fig. 12.5.4 Joseph Priestley
Production of Carbon Dioxide Gas
Carbon dioxide gas can be prepared in the school laboratory by reacting an acid, such as hydrochloric acid, with a carbonate, such as calcium carbonate. The word equation for this reaction is:
