The general formula of aldehyde is

Options

A. `-COOH`
B. `-underset(H)underset(|)C=O`
C. `-OH`
D. CO

Explanation

To determine the general formula of aldehyde, we can follow these steps:

### Step 1: Understand the Functional Group
Aldehydes are characterized by the presence of a specific functional group known as the carbonyl group. This group is represented as -CHO.

### Step 2: Analyze the Structure
In the -CHO functional group:
- The carbon (C) is double-bonded to an oxygen (O) atom.
- The same carbon is also single-bonded to a hydrogen (H) atom.
- Additionally, this carbon can be bonded to a hydrocarbon chain or an alkyl group, represented as 'R'.

### Step 3: General Formula Derivation
The general formula for aldehydes can be derived from the structure:
- The carbonyl carbon contributes one carbon atom.
- The hydrogen atom contributes one hydrogen atom.
- The alkyl group (R) can vary in size and composition, but it typically contains 'n' carbon atoms.

Thus, the general formula for aldehydes can be expressed as:
\[ \text{C}_n\text{H}_{2n+1}\text{CHO} \]
This simplifies to:
\[ \text{C}_n\text{H}_{2n+2}\text{O} \]
where 'n' is the number of carbon atoms in the alkyl group.

### Conclusion
The general formula of aldehyde is:
\[ \text{C}_n\text{H}_{2n+1}\text{CHO} \]
or simply represented as:
\[ \text{C}_n\text{H}_{2n+2}\text{O} \]