Question
Chemistry Question on Acids, Bases And Salts
Which of the following gives a positive Tollens test?
(A) Phenylethanal
(B) Acetophenone
(C) Formic acid
(D) Benzene carbaldehyde
Choose the correct answer from the options given below:
A
A, B, and D only
B
A, B, and C only
C
A, B, C, and D
D
A, C, and D only
Answer
A, B, and D only
Explanation
Solution
The Tollens test is used to detect aldehydes, as they reduce Tollens' reagent to metallic silver. Phenylethanal and benzene carbaldehyde are aldehydes and will give a positive Tollens test. Formic acid, though a carboxylic acid, can also react with Tollens' reagent to give a positive test. Acetophenone is a ketone and does not give a positive Tollens test.