Carbonyl Compounds – Structure, Properties, and Reactions

Carbonyl Compounds are organic compounds containing a carbon atom double bonded to an oxygen atom (C=O). They play an important role in organic chemistry and are found in Aldehydes, Ketones, Carboxylic Acids, Esters, and Amides.

Related topics: Wikipedia.

Structure of Carbonyl Group

The carbonyl group consists of a carbon atom double bonded to an oxygen atom (C=O). The bond is polar due to the electronegativity difference between carbon and oxygen, making the carbon electrophilic.

Properties of Carbonyl Compounds

• Polarity: The C=O bond is polar, making carbonyls reactive.
• Boiling Point: Higher than hydrocarbons but lower than alcohols due to dipole-dipole interactions.
• Solubility: Lower members are soluble in water due to hydrogen bonding.

Important Reactions

• Nucleophilic Addition Reactions: Common for aldehydes and ketones.
• Oxidation: Aldehydes oxidize to carboxylic acids, ketones resist oxidation.
• Reduction: Both reduce to alcohols with suitable reagents.

Applications

Carbonyl compounds are used in perfumes, solvents, plastics, pharmaceuticals, and in many biochemical processes.

Multiple Choice Questions (MCQs)

1. Which of the following is a carbonyl compound?
   a) CH₄
   b) CH₃CHO
   c) C₂H₆
   d) CH₃OH
   ✅ Answer: (b) CH₃CHO
2. The carbonyl carbon is:
   a) Nucleophilic
   b) Electrophilic
   c) Neutral
   d) None
   ✅ Answer: (b) Electrophilic

True/False

• All carbonyl compounds have a C=O group. ✅ True
• Ketones can easily be oxidized to acids. ❌ False

Fill in the Blanks

• The bond between carbon and oxygen in the carbonyl group is ________. ✅ Answer: Polar covalent
• Aldehydes oxidize to ________. ✅ Answer: Carboxylic acids

Quick Quiz

Q: Why is the carbon atom in a carbonyl group electrophilic?

Ans: Because oxygen is more electronegative, it pulls electron density, leaving the carbon electron-deficient and susceptible to nucleophilic attack.