To determine which formula represents a ketone, we need to understand the functional group that defines a ketone. A ketone is characterized by the presence of a carbonyl group (C=O) which is bonded to two carbon atoms.
Let's examine each of the given formulas:
1. CH3COCH3: This formula can be written as [tex]\( CH3 - CO - CH3 \)[/tex]. Here, the central carbon atom (C) is double-bonded to an oxygen atom (O) and single-bonded to two other carbon atoms (C), fulfilling the criteria for a ketone.
2. C2H5OH: This formula represents ethanol, which contains a hydroxyl group (-OH) rather than a carbonyl group (C=O). Therefore, this is an alcohol, not a ketone.
3. CH3COOH: This formula represents acetic acid. It has a carboxyl group (-COOH), which includes a carbonyl group but it is bonded to a hydroxyl group (-OH), making it a carboxylic acid, not a ketone.
4. CH3COOCH3: This formula is that of methyl acetate, an ester. It consists of a carbonyl group (C=O) bonded to an oxygen atom (O) which is further bonded to a carbon atom, typically not fulfilling the criteria of a ketone where the carbonyl group should be between two carbon atoms.
After examining each formula, we can see that the correct representation of a ketone among the choices provided is:
1) CH3COCH3
So, the correct answer is choice 1.
