Ethane, ethene, ethanoic acid, ethyne, ethanol, select the following:
The compound with -COOH as the part of its structure.

Explanation

To solve the question of identifying the compound with the -COOH (carboxylic acid) functional group from the given list (ethane, ethene, ethanoic acid, ethyne, ethanol), we can follow these steps:

### Step 1: Understand the Functional Group
The -COOH group is known as the carboxylic acid functional group. It consists of a carbonyl group (C=O) and a hydroxyl group (O-H) attached to the same carbon atom.

### Step 2: Analyze Each Compound
We will analyze each compound to see if it contains the -COOH functional group.

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