Which of the following test is used to confirm aldehyde group
(a) Schiff test
(b) Tollens Test
(c) Both of the above
Answers
Answer:
Tollens Test
Explanation:
Tollen's test for Aldehydes;;
Standards:
Cyclohexanone and Benzaldehyde
Procedure:
Add one drop or a few crystals of unknown to 1 mL of the freshly prepared Tollens reagent. Gentle heating can be employed if no reaction is immediately observed.
Tollens reagent: Into a test tube which has been cleaned with 3M sodium hydroxide, place 2 mL of 0.2 M silver nitrate solution, and add a drop of 3M sodium hydroxide. Add 2.8% ammonia solution, drop by drop, with constant shaking, until almost all of the precipitate of silver oxide dissolves. Don't use more than 3 mL of ammonia. Then dilute the entire solution to a final volume of 10 mL with water.
Positive test:
Formation of silver mirror or a black precipitate is a positive test.
Complications:
The test tube must be clean and oil-free if a silver mirror is to be observed.
Easily oxidized compounds give a positive test. For example: aromatic amine and some phenols.
Cleaning up:
Place all solutions used in this experiment in an appropriate waste container.
HOPE THIS HELPS YOU ,,
¶¶ THANK YOU ¶¶ ,,