To determine which functional group represents an ester, let's first recall what an ester is in organic chemistry.
An ester typically has the general structure:
[tex]\[ R-\text{C}(\text{O})-\text{O}-R' \][/tex]
Here,
- "R" and "R'" are alkyl or aryl groups (which can be the same or different),
- The carbon (C) is double-bonded to an oxygen (O),
- The carbon (C) is also single-bonded to another oxygen (O).
Now, let's examine the given options:
1. [tex]\( R-\frac{O}{C}-R \)[/tex]
2. [tex]\( R-\frac{O}{C}-O R \)[/tex]
3. None of the above
Option 1:
[tex]\[ R-\frac{O}{C}-R \][/tex]
This structure does not match the ester functional group structure because it doesn't have the second oxygen atom bonded to the carbon. This structure more likely represents a ketone or aldehyde (depending on the specific arrangement).
Option 2:
[tex]\[ R-\frac{O}{C}-O R \][/tex]
This structure does match the ester functional group. It has a carbon atom double-bonded to one oxygen and single-bonded to another oxygen, with the second oxygen bonded to an alkyl/aryl group (R).
Option 3:
None of the above. Given that option 2 already matches the ester functional group, this option is incorrect.
Therefore, the correct answer is:
[tex]\[ R-\frac{O}{C}-O R \][/tex]
This represents the ester functional group.
