In which of the following compounds -OH is the functional group ?

Options

A. Butanone
B. Butanol
C. Butanoic
D. Butanal

Explanation

To determine in which of the given compounds the -OH group is the functional group, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Functional Group**: The -OH group is known as the hydroxyl group, which is the functional group for alcohols.

2. **Identify the General Formula for Alcohols**: The general formula for alcohols is CnH2n+1OH. This indicates that one hydrogen atom in an alkane is replaced by an -OH group.

3. **Recognize the Naming Convention**: According to IUPAC nomenclature, alcohols are named by adding the suffix "-ol" to the name of the corresponding alkane. For example, butanol is an alcohol derived from butane.

4. **Analyze the Options**: Look at the given compounds and identify which one has the suffix "-ol". This will help in identifying the alcohol.

5. **Determine the Structure**: For butanol, the structure is C4H9OH. This confirms that butanol contains the -OH functional group.

6. **Eliminate Other Options**: Check other options to see if they contain different functional groups:
- If a compound has a carbonyl group (C=O), it is a ketone or aldehyde.
- If it has a carboxylic group (-COOH), it is a carboxylic acid.

7. **Conclusion**: After analyzing the options, the only compound that contains the -OH functional group is butanol.

### Final Answer:
The compound in which -OH is the functional group is **butanol**.

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