In the reaction `HIO_3` acts as

Options

A. A. a catalyst
B. B. a halogen carrier
C. C. an oxidizing agent
D. D. a reducing agent.

Answer

To determine the role of `HIO3` in the reaction involving D-glucose, we can follow these steps:

### Step 1: Identify the Reactant
The reactant in this reaction is D-glucose, which has the molecular formula C₆H₁₂O₆.

### Step 2: Determine the Oxidation State of Carbon in Glucose
To find the oxidation state of carbon in glucose, we can use the formula:
\[ 6X + 12(+1) + 6(-2) = 0 \]
Where:
- \( X \) is the oxidation state of carbon.
- There are 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms.

Calculating:
\[ 6X + 12 - 12 = 0 \]
\[ 6X = 0 \]
\[ X = 0 \]

Thus, the oxidation state of carbon in glucose is 0.

### Step 3: Identify the Products of the Reaction
In the reaction, one of the products is formic acid (HCOOH) and another product is formaldehyde (HCHO).

### Step 4: Determine the Oxidation State of Carbon in the Products
1. **For Formic Acid (HCOOH)**:
\[ X + 2(+1) + 2(-2) = 0 \]
\[ X + 2 - 4 = 0 \]
\[ X - 2 = 0 \]
\[ X = +2 \]

The oxidation state of carbon in formic acid is +2.

2. **For Formaldehyde (HCHO)**:
\[ X + 2(+1) + (-2) = 0 \]
\[ X + 2 - 2 = 0 \]
\[ X = 0 \]

The oxidation state of carbon in formaldehyde is 0.

### Step 5: Analyze the Changes in Oxidation States
- In glucose, the oxidation state of carbon is 0.
- In formic acid, the oxidation state of carbon is +2.
- In formaldehyde, the oxidation state of carbon remains 0.

### Step 6: Conclusion
Since 5 out of the 6 carbon atoms in glucose are oxidized from an oxidation state of 0 to +2, we can conclude that `HIO3` (or `HIO4` as mentioned in the transcript) is acting as an oxidizing agent in this reaction. It facilitates the oxidation of glucose.

### Final Answer
`HIO3` acts as an oxidizing agent in the reaction involving D-glucose.

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