To solve the question, we first need to understand what defines a ketone. A ketone is an organic compound characterized by a carbonyl group (a carbon double-bonded to an oxygen) bound to two carbon atoms. The general formula for a ketone is [tex]\( R_1 - CO - R_2 \)[/tex], where [tex]\( R_1 \)[/tex] and [tex]\( R_2 \)[/tex] are alkyl or aryl groups.
To identify the structural formula of a ketone among the given options, we'll look for these characteristics:
- A carbonyl group's carbon (C=O)
- The carbonyl carbon is attached to two other carbon atoms
Considering these criteria, let's analyze each option:
A.
[tex]\[ \text{O} \][/tex]
[tex]\[ || \][/tex]
[tex]\[ \text{C} - \text{R}_1 - \text{R}_2 \][/tex]
This structure represents a functional group that's not a ketone, as the carbonyl carbon is not attached to two other carbon atoms.
B.
[tex]\[ \text{R}_1 - \text{C} = \text{O} - \text{R}_2 \][/tex]
This structural formula is ambiguous without more details about [tex]\(R_1\)[/tex] and [tex]\(R_2\)[/tex].
D.
[tex]\[ \text{O} \][/tex]
[tex]\[ || \][/tex]
[tex]\[ \text{R}_1 - \text{C} - \text{R}_2 \][/tex]
This is a clear representation of a ketone, showing a carbonyl carbon double-bonded to an oxygen and bonded to two other carbon atoms.
Given the ketone definition and necessary structural characteristics, the correct structural formula for a ketone compound is option D.
