Glucose and Galactose are having identical configuration in all the positions except position.
`C-n`.
The numerical value of n is_____.

Explanation

To determine the numerical value of \( n \) where glucose and galactose differ in configuration, we will follow these steps:

### Step 1: Understand the Structures of Glucose and Galactose
- Glucose and galactose are both monosaccharides with the same molecular formula \( C_6H_{12}O_6 \).
- They differ in the configuration around one specific carbon atom.

### Step 2: Draw the Structure of Glucose
- The structure of glucose can be represented as follows:
- It has an aldehyde group (C=O) at the first carbon.
- The hydroxyl groups (OH) are attached to the second, third, and fourth carbons, and the fifth carbon has a CH2OH group.

### Step 3: Draw the Structure of Galactose
- The structure of galactose is similar to glucose but differs in the configuration at one carbon:
- The first carbon is also an aldehyde group.
- The hydroxyl groups are arranged differently compared to glucose.

### Step 4: Identify the Carbon with Different Configuration
- Compare the configurations of glucose and galactose:
- At the second carbon (C2), both have the same configuration.
- At the third carbon (C3), both have the same configuration.
- At the fourth carbon (C4), the configuration differs:
- In glucose, the OH group is on the right.
- In galactose, the OH group is on the left.

### Step 5: Determine the Value of \( n \)
- Since the only difference in configuration occurs at the fourth carbon, we conclude that \( n = 4 \).

### Final Answer
The numerical value of \( n \) is **4**.

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