Question

F. Basic Oxidation 1. Place 1 drop of the sample in a test tube 2. Add 1 drop of 2% KM 0 3. Add 3 drops of 10% NaOH 4. Add 7 drops water. 5. Observe the rate of color change.

Hydrocarbons Experiment

Answer 1

This question is regarding Laboratory experiment for determining structure or functionality of a hydrocarbon.Under given alkaline KMnO₄ conditions alkenes / cycloalkenes / alkynes / alkyl substituents on the aromatic ring (Benzylic position) oxidized. KMnO₄ is a strong oxidizing agent, it reactivity depends on reaction conditions.

1.

Chloro Methane ( CH₃-Cl ) : In this reaction condition CH₃-Cl is not oxidized ; No reaction occures.

The purple color of the potassium permanganate does not changes to brown for longer period.

Cyclohexane (C₆H₁₂ ) :  In this reaction condition Cyclohexane (C₆H₁₂ ) is not oxidized ; No reaction occures.

The purple color of the potassium permanganate does not changes to brown for longer period.

None of the compound contains functionality, which can be oxidised by KMnO_4.

2.

Toluene : It is oxidized by KMnO₄ to benzoic acid, methyl group on benzene ring is suseptible to oxidation by alkaline KMnO_4.

C₆H₅-CH₃ (Toluene)  $\rightarrow$  C₆H₅-COOH (Benzoic acid )

Purple color of the potassium permanganate changes to brown (due to manganese dioxide (MnO2) indicates a positive reaction) in little time, indicating oxidation reaction.

This compound contains functionality, which can be oxidised by KMnO_4.

Benzene (C₆H₆ ) :  

C₆H₆$\rightarrow$ No Reaction

In this reaction Benzene is not oxidized ; No reaction occures.

The purple color of the potassium permanganate does not changes to brown for longer period.

This compound does not contains functionality, which can be oxidised by KMnO_4.