The Earth atmosphere is a mixture of gaseous elements and compounds. We can prepare samples of common gases such as hydrogen, oxygen and carbon dioxide in the laboratory and examine their properties and reactions.
Preparing and collecting hydrogen gas
We prepare hydrogen by reacting zinc or magnesium with dilute hydrochloric acid:
Zn + 2HCl → ZnCl2 + H2
Mg + 2HCl → MgCl2 + H2
Test for hydrogen
A lit splint applied to hydrogen gas will result in a popping sound.