Baeyer’s reagent is an alkaline solution of cold potassium permanganate(KMNO4) of violet colour solution. It is a strong oxidizing agent. As this solution interacts with a double bond compound the colour disappears and becomes colourless. Baeyer’s test is essentially an unsaturation test. This test for unsaturation involves adding bromine to a double bond, which results in the fast decolourization of bromine water or bromine dissolved in carbon tetrachloride.
- Baeyer’s reagent is an alkaline potassium permanganate solution in a very cold dilute solution.
- It’s a light violet or purple-coloured solution.
- Baeyer’s reagent is a powerful oxidising reagent that is used to determine if a hydrocarbon has double or triple bonds.
- As a result, it denotes that hydrocarbon molecules are unsaturated.
- When a purple colour reagent is introduced to ethylene, it produces a colourless ethane-1,2-diol solution.
Baeyer’s Reagent Preparation
- To make a 1 per cent potassium permanganate solution, dissolve 1 gram of solid KMnO4 in 100 mL distilled water.
- The stoppered container is filled with 10 grams of anhydrous sodium carbonate (Na2CO3), which is shaken until entirely dissolved.
- When not in use, store the solution in a dark, cold cabinet to keep it fresh.
Properties of KMNO4
Few properties of KNMO4 are,
- It dissolves in water to give intensely pink or purple solutions.
- On evaporation, it leaves prismatic purplish-black glistening crystals.