Question

Identify the catalyst X used in the following reaction.

\[\ce{CH3CH2Br + 2[H] ->[X] CH3 - CH3 + HBr}\]

Options

• K₂Cr₂O₇

• KMnO₄

• CaO, Δ

• Zn-Cu couple in alcohol

Answer 1

Zn-Cu couple in alcohol

Explanation:

\[\ce{CH3CH2Br + 2[H] ->[Zn-Cu (X)][Alcohol] CH3 - CH3 + HBr}\]

In alcohol, [X] is a Zn-Cu couple. When ethyl bromide is treated with the Zn-Cu pair and alcohol in this reaction, ethyl bromide is converted to ethane. This is a redox reaction in a sense. In it, ethyl bromide is reduced to form an ethyl organometallic and Br⁻, which is then protonated by ethanol to form ethane.