Question

What is the most widely used general test for identifying carbohydrates?

• A. Biuret Test
• B. Benedict’s Test
• C. Molisch Test
• D. Iodine Test

Hint:

Molisch Test = General test for all carbohydrates → Violet ring confirms presence.

Answer 1

The Correct Option is C

Concept: Carbohydrates can be identified using several qualitative chemical tests. Among these, one test is considered a general test applicable to all types of carbohydrates.
Step 1: Understanding Molisch Test.
Molisch Test is a general test used to detect the presence of carbohydrates.
Step 2: Principle of the test.
Carbohydrates, when treated with concentrated sulfuric acid, undergo dehydration to form furfural or hydroxymethylfurfural, which reacts with Molisch reagent (α-naphthol) to produce a violet ring.
Step 3: Observation.
Formation of a purple/violet ring at the junction of two layers indicates the presence of carbohydrates.
Step 4: Eliminating other options.

• Biuret Test: Detects proteins
• Benedict’s Test: Detects reducing sugars only
• Iodine Test: Specific for starch

Step 5: Conclusion.
Thus, Molisch Test is the most widely used general test for identifying carbohydrates.