To distinguish between glucose and fructose, we can analyze the behavior of these two sugars with different reagents. Here's a step-by-step solution to the question:
### Step 1: Understanding the Structure of Glucose and Fructose
- Glucose is an aldose, meaning it contains an aldehyde group (-CHO).
- Fructose is a ketose, meaning it contains a ketone group (C=O).
### Step 2: Testing with Bromine Water
- **Bromine Water**: This reagent can oxidize aldehydes but not ketones.
- When glucose (aldose) is treated with bromine water, it is oxidized to gluconic acid, resulting in a positive test.
- Fructose (ketose), however, does not react with bromine water in the same way, leading to a negative test.
- **Conclusion**: Bromine water can distinguish between glucose and fructose because glucose gives a positive test while fructose does not.
### Step 3: Testing with Tollen's Reagent
- **Tollen's Reagent**: This reagent is used to test for aldehydes.
- Both glucose and fructose can react with Tollen's reagent, but since fructose is a ketose, it does not provide a clear distinction.
- **Conclusion**: Tollen's reagent cannot be used to distinguish between glucose and fructose as both give a positive test.
### Step 4: Testing with Schiff's Reagent
- **Schiff's Reagent**: This reagent is also used to test for aldehydes.
- Glucose, being an aldose, would react positively with Schiff's reagent, while fructose, as a ketose, does not react.
- However, both sugars do not give a positive reaction with Schiff's reagent in the same manner, leading to a negative test for both.
- **Conclusion**: Schiff's reagent cannot distinguish between glucose and fructose since both give a negative test.
### Final Conclusion
- The only reagent that can effectively distinguish between glucose and fructose is **Bromine Water**.
- Therefore, the answer to the question is:
- (I) Bromine Water: Yes, it can distinguish.
- (II) Tollen's Reagent: No, it cannot distinguish.
- (III) Schiff's Reagent: No, it cannot distinguish.
### Summary
The correct reagent to distinguish glucose from fructose is **Bromine Water**.
