Question

Write the structural formula of ethanoic acid.

Hint:

Ethanoic acid is commonly known as acetic acid, the main component of vinegar.

Answer 1

Step 1: Understanding the Concept:
The name "ethanoic acid" gives us two clues: "eth-" means 2 carbon atoms, and "-oic acid" means it contains a carboxylic acid functional group (\(-\text{COOH}\)).

Step 2: Detailed Explanation:
Start with a two-carbon skeleton: \(\text{C}-\text{C}\).
Turn one of the carbons into a carboxyl group: \(\text{C}-\text{C}(=\text{O})\text{OH}\).
Fill the remaining valencies of the first carbon with hydrogen atoms. Carbon needs 4 bonds, so it gets 3 hydrogens.
The resulting formula is \(\text{CH}_3\text{COOH}\).
The fully expanded structural formula shows all bonds:
One carbon is bonded to three hydrogens.
It is single-bonded to a second carbon.
The second carbon is double-bonded to an oxygen atom and single-bonded to a hydroxyl (\(-\text{OH}\)) group.

Step 3: Final Answer:
The structural formula is \(\text{CH}_3\text{COOH}\).