Question

What would be the products obtained when a mixture of p-Methoxy benzaldehyde and Methanal are heated with 50% concentrated Caustic soda solution?

• A. p-Methoxy sodium benzoate and sodium acetate.
• B. p-Methoxy benzyl alcohol and sodium formate.
• C. p-Methoxy benzyl alcohol and methanol.
• D. p-Methoxy sodium benzoate and sodium formate.

Hint:

The Cannizzaro reaction occurs with aldehydes that lack an α-hydrogen, resulting in disproportionation to form an alcohol and a carboxylate anion. Keep an eye out for aldehydes without α-hydrogens in reaction schemes.

Answer 1

The Correct Option is B

The reaction described is an example of the Cannizzaro reaction, which occurs when an aldehyde (lacking an α-hydrogen) is treated with a strong base (like concentrated sodium hydroxide). The reaction leads to disproportionation, where one molecule is reduced to an alcohol, and the other is oxidized to a carboxylate anion. In this case: - p-Methoxy benzaldehyde undergoes the Cannizzaro reaction. - Methanal (formaldehyde) also undergoes the same process. The main products: - The reduction of one aldehyde molecule (in this case, p-Methoxy benzaldehyde) leads to the formation of p-Methoxy benzyl alcohol. - The other aldehyde (formaldehyde) is oxidized to form sodium formate. Therefore, the correct products are p-Methoxy benzyl alcohol and sodium formate.