Question

Consider the above reaction and identify the missing reagent/chemical.

 

• A. DIBAL-H
• B. B₂H₆
• C. Red Phosphorus
• D. CaO

Answer 1

The Correct Option is D

To identify the missing reagent/chemical in the given reaction, let's analyze the reaction step by step.

The reaction provided is a common decarboxylation reaction of a carboxylic acid salt, specifically sodium propanoate (CH₃CH₂COO^-Na⁺). This reaction requires a strong base, such as sodium hydroxide (NaOH), and a catalyst or assistant like calcium oxide (CaO) for the reaction to proceed.

The reaction can be described with the equation:

\(2 \, \text{CH}_3\text{CH}_2\text{COONa} + 2 \, \text{NaOH} \xrightarrow{\text{CaO, Heat}} 2 \, \text{CH}_3\text{CH}_3 + \text{Na}_2\text{CO}_3\)

Explanation of options:

• DIBAL-H: Typically used for reduction reactions and would not facilitate decarboxylation.
• B₂H₆: Commonly used for hydroboration, not relevant here.
• Red Phosphorus: Used in reduction or conversion processes with iodine, not applicable for decarboxylation.
• CaO: Used as a catalyst in decarboxylation reactions to convert carboxylates to hydrocarbons.

Thus, the correct reagent required for the reaction is Calcium Oxide (CaO), which assists in the decarboxylation process, leading to the formation of ethane (CH₃CH₃) from sodium propanoate.

Correct Answer: CaO