Carboxylic group is present in

Options

A. ethylene
B. methanoic acid
C. formaldehyde
D. ethanol

Explanation

To determine whether a compound contains a carboxylic group, we need to understand what a carboxylic group is. A carboxylic group is characterized by the presence of a carbonyl group (C=O) and a hydroxyl group (–OH) attached to the same carbon atom. This functional group is represented as –COOH.

### Step-by-Step Solution:

1. **Identify the Functional Group**:
- The carboxylic group is denoted as –COOH. It consists of a carbon atom double-bonded to an oxygen atom (C=O) and single-bonded to a hydroxyl group (–OH).

2. **Examine the Given Compounds**:
- The question mentions ethylene and formaldehyde.
- **Formaldehyde**: Its structure is HCHO, which contains an aldehyde group (–CHO) but does not have a carboxylic group (–COOH).
- **Ethanol**: Its structure is C2H5OH, which contains an alcohol group (–OH) but lacks the carbonyl component necessary for a carboxylic group.

3. **Conclusion**:
- Neither formaldehyde nor ethanol contains a carboxylic group. Therefore, the answer to the question "Carboxylic group is present in" is neither of the compounds mentioned.

### Final Answer:
The carboxylic group is not present in either formaldehyde or ethanol.