Question

The compounds which give positive Fehling's test are:

Choose the CORRECT answer from the options given below:

• A. (A), (C) and (D) Only
• B. (A), (D) and (E) Only
• C. (C), (D) and (E) Only
• D. (A), (B) and (C) Only

Hint:

Fehling's test is a chemical test used to distinguish between aldehydes and ketones. Aldehydes give a positive test, while most ketones do not. However, \(\alpha\)-hydroxy ketones also give a positive test.

Answer 1

The Correct Option is C

Fehling's test is a chemical test used to differentiate between reducing and non-reducing sugars. It specifically identifies aldehydes, as they are oxidized by Fehling’s solution while other functional groups are not.

In order to determine which compounds will give a positive result in the Fehling's test, we need to identify the presence of an aldehyde group. Compounds containing ketones or other functional groups typically do not produce a positive Fehling’s test result unless they can isomerize into an aldehyde.

Let us analyze the given options:

1. Option (C): This compound is an aldehyde. Hence, it will reduce Fehling's solution and give a positive test.
2. Option (D): This compound is also an aldehyde which can easily reduce the Fehling’s solution, yielding a positive result.
3. Option (E): If this compound is an aldehyde or a compound that can tautomerize to an aldehyde, it will result in a positive test as well.

As compounds (C), (D), and (E) demonstrate the presence of aldehyde groups (or are capable of tautomerizing into one), they give a positive Fehling’s test.

Therefore, the correct answer is: (C), (D) and (E) Only