Alkanals can be differentiated from alkanones by reaction with
Alkanals can be differentiated from alkanones by reaction with
- A) 2, 4 - dinitrophenylhydrazine
- B) hydrogen cyanide
- C) sodium hydrogen sulphite
- D) Tollens' reagent
Correct Answer: D) Tollens' reagent
Explanation
This Chemistry question is asking how to differentiate between alkanals and alkanones. The options are 2, 4 - dinitrophenylhydrazine, hydrogen cyanide, sodium hydrogen sulphite, and Tollens' reagent. The correct answer is Tollens' reagent.
Tollens' reagent is a solution of silver nitrate and ammonia. It is used to test for the presence of aldehydes, such as alkanals. When Tollens' reagent is added to an aldehyde, it is oxidized to a carboxylic acid and a silver mirror is formed on the inside of the test tube. This reaction does not occur with ketones, such as alkanones, so Tollens' reagent can be used to differentiate between the two.
2,4-dinitrophenylhydrazine is another common reagent used to differentiate between aldehydes and ketones. When 2,4-dinitrophenylhydrazine is added to an aldehyde or ketone, a yellow or orange precipitate is formed. However, this test cannot distinguish between alkanals and alkanones because both produce the same precipitate.
Hydrogen cyanide and sodium hydrogen sulphite are not commonly used to differentiate between alkanals and alkanones.
In summary, Tollens' reagent can be used to differentiate between alkanals and alkanones because it reacts with aldehydes to form a silver mirror, while ketones do not react. For more information, please see the recommended textbooks.