question_answer

  Account for the following :                          Formaldehyde gives Cannizzaro's reaction   whereas acetaldehyde does not.

Answer:

  Only those aldehydes will give Cannizzaro's reaction which do not contain a-hydrogen. Since formaldehyde has no cc-hydrogen, it will give Cannizzaro's reaction. But acetaldehyde has a-hydrogen, so it does not give Cannizzaro's reaction.