• Bromine test: When $$5\%$$ solution of bromine in carbon tetrachloride is added to an alkene, it gets decolourized. This Indicate the presence of unsaturation in organic compound.
• Bayer's test: When alkene is oxidised with cold,. alkaline $$KMnO_{4}$$, diol is formed. The $$KMnO_{4}$$ gets decolourized. This indicates the presence of unsaturation of organic compound.