Question

Which of the following has higher priority?
Group of answer choices

-COCH3

-CH2CH2OH

-CH2CH3

-CH3

Answer 1

To determine the priority of the given groups based on the Cahn-Ingold-Prelog priority rules, we need to consider their atomic numbers and the specific functional groups present in each choice.

1. **-COCH3 (acetyl group)**: This group features a carbonyl (C=O) followed by a methyl group. The presence of the carbonyl gives this group higher priority because of the double bond to oxygen.

2. **-CH2CH2OH (ethanol)**: This contains a hydroxyl group (-OH), which typically gives it a higher priority than alkyl groups but lower than groups with carbonyls.

3. **-CH2CH3 (ethyl group)**: This is a simple alkyl group with no additional functional groups.

4. **-CH3 (methyl group)**: This is the simplest alkyl group.

To rank them based on priority:
- **-COCH3** has the highest priority due to the carbonyl.
- **-CH2CH2OH** is next because of the hydroxyl group.
- **-CH2CH3** follows as an alkyl chain.
- **-CH3** has the lowest priority.

Thus, the order from highest to lowest priority is:
1. -COCH3
2. -CH2CH2OH
3. -CH2CH3
4. -CH3

So, **-COCH3 has the highest priority** among the given choices.