Question

Which of the following reagents can be used to distinguish between alkenes and alkanes?

• A. Fehling's solution
• B. Baeyer's reagent (dilute alkaline KMnO\(_4\))
• C. Benedict's solution
• D. Sodium metal

Hint:

Baeyer's test is a quick method to differentiate alkenes (unsaturated) from alkanes (saturated).

Answer 1

The Correct Option is B

- Baeyer's test uses dilute alkaline potassium permanganate (KMnO\(_4\)), which is purple in color. 
- Alkenes react with Baeyer's reagent causing the purple color to disappear (decolorize) due to oxidation of the double bond. 
- Alkanes do not react with Baeyer's reagent, so the purple color remains. 
- Fehling's and Benedict's solutions are used for detecting aldehydes, not alkenes or alkanes. 
- Sodium metal reacts with water and alcohols but cannot distinguish between alkenes and alkanes. 
Answer: \(\boxed{\text{B}}\)