Question

Match each type of reduction to its reagent:

• A. Clemmensen Reduction → Zinc amalgam with hydrochloric acid
• B. Wolff-Kishner Reduction → Hydrazine and potassium hydroxide with heat
• C. Rosenmund Reduction → Hydrogen gas with palladium on barium sulfate

Hint:

Always associate the type of reduction with the environment and reagents. Clemmensen is acidic, Wolff-Kishner is basic, and Rosenmund uses palladium.

Answer 1

The Correct Option is A

Step 1: Understanding each reduction.
- Clemmensen reduction is carried out under acidic conditions, typically using zinc amalgam and hydrochloric acid.
- Wolff-Kishner reduction is performed under basic conditions, using hydrazine and potassium hydroxide with heat.
- Rosenmund reduction involves hydrogen gas and palladium on barium sulfate, often used to reduce acyl chlorides to aldehydes.
Step 2: Conclusion.
Thus, the correct matches are: (A) Clemmensen Reduction → Zinc amalgam with hydrochloric acid (B) Wolff-Kishner Reduction → Hydrazine and potassium hydroxide with heat (C) Rosenmund Reduction → Hydrogen gas with palladium on barium sulfate

Answer 2

Step 1: Clemmensen reduction works in acid — it uses zinc amalgam with hydrochloric acid.

Step 2: Wolff-Kishner reduction works in base — it uses hydrazine with potassium hydroxide and heat.

Step 3: Rosenmund reduction uses hydrogen gas with palladium on barium sulfate to turn acid chlorides into aldehydes.

Step 4: So the correct matching is exactly as in option (A).

Answer 3

Why each reagent actually works: Clemmensen reduction needs an acidic medium because the substrate has to tolerate strong acid, zinc amalgam supplies electrons while HCl protonates the intermediate so the oxygen leaves as water. Wolff-Kishner instead converts the carbonyl to a hydrazone first, and hot potassium hydroxide then breaks it down through loss of nitrogen gas, a route that only works in base. Rosenmund reduction deliberately poisons the palladium catalyst with barium sulfate so hydrogenation stops at the aldehyde stage instead of running on to the alcohol. Checked this way, every pairing given, Clemmensen with zinc amalgam and HCl, Wolff-Kishner with hydrazine and KOH, and Rosenmund with hydrogen and palladium on barium sulfate, holds up, confirming option (A).