Determination of oil unsaturation using bromine water
name: Qualitative reaction for double bonds is the reaction of unsaturated compounds with bromine water.
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Vegetable oils are triglycerides extracted from a plant. Triglycerides are an ester derived from glycerol and three fatty acids. Fatty-acid-residues can be saturated and unsaturated compounds. Unsaturated compounds have double bonds (C=C) between carbon atoms. Unsaturated fats have a lower melting point and are more likely to be liquid at room temperature. Vegetable oils are more unsaturated then animal fats.
The double bonds have the ability to attach halogen atoms. The qualitative reaction for double bonds is the reaction of unsaturated compounds with bromine water:
-CH2-CH=CH-CH2- + Br2 → -CH2-CHBr-CHBr-CH2-
Discoloration of bromine water is the qualitative indication of this reaction.