The test used for identifying carbon-carbon double fond in an alkene is

Options

A. Baeyer
B. Carbylamine
C. Lassaigne
D. Silver mirror

Answer

To identify the carbon-carbon double bond in an alkene, the test used is the Baeyer test. Here’s a step-by-step explanation of how this test works:

### Step-by-Step Solution:

1. **Understanding Alkenes**:
- Alkenes are hydrocarbons that contain at least one carbon-carbon double bond (C=C). An example is ethene (C2H4).

2. **Reagent Used**:
- The reagent used in the Baeyer test is cold, dilute alkaline potassium permanganate (KMnO4).

3. **Reaction Mechanism**:
- When an alkene like ethene reacts with cold dilute alkaline KMnO4, it undergoes oxidation. The double bond reacts with the permanganate ions.

4. **Product Formation**:
- The reaction leads to the formation of a diol (specifically, ethylene glycol in the case of ethene) and manganese dioxide (MnO2) as a precipitate.

5. **Observation**:
- The appearance of a brown precipitate of manganese dioxide (MnO2) indicates a positive result for the presence of a carbon-carbon double bond.

6. **Conclusion**:
- Therefore, the Baeyer test is a reliable method for identifying the presence of carbon-carbon double bonds in alkenes.

### Final Answer:
The test used for identifying carbon-carbon double bonds in an alkene is the **Baeyer test** (using cold dilute alkaline KMnO4).

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