Which of the following reagents would convert an aldose into corresponding aldonic acid?

Options

A. Tollen's reagent
B. Fehling's solution
C. Bromine water
D. Red P+HI

Explanation

To convert an aldose into its corresponding aldonic acid, we can use several reagents that facilitate this oxidation reaction. Here’s a step-by-step breakdown of the process:

### Step 1: Understanding Aldoses and Aldonic Acids
- Aldoses are a type of sugar that contains an aldehyde group (-CHO). Glucose is a common example of an aldose.
- Aldonic acids are the oxidized forms of aldoses, where the aldehyde group is oxidized to a carboxylic acid group (-COOH).

### Step 2: Identifying the Reagents
The question lists several reagents: Tollens' reagent, Fehling's solution, bromine water, and red phosphorus with HI. We need to determine which of these can oxidize an aldose to an aldonic acid.

### Step 3: Evaluating Each Reagent
1. **Tollens' Reagent (AgNO3 + NH4OH)**:
- Tollens' reagent is known for oxidizing aldehydes. When glucose reacts with Tollens' reagent, it gets oxidized to gluconic acid, and a characteristic silver mirror forms.
- **Conclusion**: Tollens' reagent can convert an aldose to an aldonic acid.

2. **Fehling's Solution**:
- Fehling's solution contains copper(II) ions that can oxidize aldehydes. When glucose is treated with Fehling's solution, it is oxidized to gluconic acid, producing a red precipitate of Cu2O.
- **Conclusion**: Fehling's solution can also convert an aldose to an aldonic acid.

3. **Bromine Water**:
- Bromine water is another oxidizing agent that can oxidize aldehydes. Glucose reacts with bromine water to form gluconic acid.
- **Conclusion**: Bromine water can convert an aldose to an aldonic acid.

4. **Red Phosphorus and HI**:
- Red phosphorus and HI do not oxidize aldoses; instead, they can reduce sugars or convert them into hydrocarbons.
- **Conclusion**: Red phosphorus and HI do not convert an aldose to an aldonic acid.

### Step 4: Final Answer
Based on the evaluations:
- The reagents that can convert an aldose into the corresponding aldonic acid are **Tollens' reagent, Fehling's solution, and bromine water**. Therefore, the correct options are 1, 2, and 3.

### Summary
The reagents that can convert an aldose into the corresponding aldonic acid are:
- **Tollens' reagent**
- **Fehling's solution**
- **Bromine water**