Functional grouos

• Carboxylic acids


  Organic compounds characterized by the presence of a carboxyl group (–COOH) functional group
• Carboxyl group


  • Consists of a carbonyl group (C=O) bonded to a hydroxyl group (–OH), both attached to the same carbon atom (the carboxyl carbon)
• Acidity of carboxylic acids


  They are weak acids, meaning they can donate a proton (H⁺ ion) when dissolved in water. This is due to the presence of the hydroxyl group, which can easily release a proton.
• Naming carboxylic acids


  1. Replace the -e ending of the corresponding alkane with -oic acid

  2. For example, methane becomes methanoic acid and ethane becomes ethanoic acid
• Carboxylic acids


  • They are polar molecules due to the electronegativity difference between carbon, oxygen, and hydrogen atoms in the functional group
  • They have higher boiling points compared to hydrocarbons of similar molecular weight due to hydrogen bonding between carboxylic acid molecules
  • Many have distinctive odors and are responsible for the smell of certain foods and substances
• Neutralization reaction of carboxylic acids

  Reaction with bases to form salts and water
• Esterification reaction of carboxylic acids

  Reaction with alcohols to form esters and water
• Reduction of carboxylic acids


  Using reducing agents like lithium aluminum hydride (LiAlH₄) to form alcohols
• • Chemical Structure: Ketones are organic compounds characterized by the presence of a carbonyl group (C=O), where the carbon atom is bonded to two other carbon atoms. The carbonyl group is flanked by two alkyl or aryl groups.
  • Functional Group: The carbonyl group consists of a carbon atom doubly bonded to an oxygen atom. In a ketone, this carbonyl group is bonded to two other carbon atoms.
  • Naming: Ketones are named by replacing the -e e
• Ketones


  • Polar molecules due to the electronegativity difference between carbon and oxygen atoms in the carbonyl group
  • Have higher boiling points compared to hydrocarbons of similar molecular weight due to dipole-dipole interactions between ketone molecules
  • Some exhibit distinctive odors, e.g. acetone has a characteristic fruity smell
• Nucleophilic addition reactions at the carbonyl carbon of ketones


  Forming products such as alcohols
• Reduction of ketones


  To secondary alcohols using reducing agents like sodium borohydride (NaBH4) or lithium aluminum hydride (LiAlH4)
• Oxidation of ketones


  To form carboxylic acids, although this reaction is less common compared to aldehydes
• Amines


  Organic compounds characterized by the presence of a nitrogen atom (N) bonded to one or more alkyl or aryl groups
• Amines


  Derivatives of ammonia (NH3), where one or more hydrogen atoms are replaced by alkyl or aryl groups
• Amino group


  The functional group in amines, consisting of a nitrogen atom bonded to two hydrogen atoms
• Types of amines


  • Primary amines
  • Secondary amines
  • Tertiary amines
• Primary amines


  • One alkyl or aryl group and two hydrogen atoms bonded to the nitrogen atom
• Secondary amines


  • Two alkyl or aryl groups and one hydrogen atom bonded to the nitrogen atom
• Tertiary amines


  • Three alkyl or aryl groups bonded to the nitrogen atom
• Naming amines


  Amines are named by adding the suffix -amine to the name of the alkyl or aryl group(s) attached to the nitrogen atom. In the case of primary and secondary amines, the prefix N- is used to indicate the position of the amino group.
• Amines


  • Polar molecules due to the electronegativity difference between nitrogen and carbon atoms
  • Soluble in polar solvents like water
  • Often have a characteristic, unpleasant odor, particularly the lower-molecular-weight ones
• Amines act as weak bases


  Readily accepting protons (H⁺ ions) to form ammonium ions (NH4⁺) in acidic conditions
• Alkylation and acylation reactions of amines

  Alkyl or acyl groups are introduced onto the nitrogen atom
• Amine salt formation


  Amines can form salts with acids, such as ammonium salts, through protonation of the amino group
• Condensation reactions of amines

  Amines can participate in condensation reactions to form imines or enamines by reacting with carbonyl compounds like aldehydes or ketones
• Phenols


  Organic compounds characterized by the presence of a hydroxyl group (-OH) attached directly to an aromatic benzene ring
• Functional group of phenols


  • The hydroxyl group is directly bonded to one of the carbon atoms in the benzene ring, making them distinct from alcohols where the hydroxyl group is attached to an aliphatic carbon chain
• Phenols


  Polar molecules due to the electronegativity difference between the oxygen atom in the hydroxyl group and the carbon atoms in the benzene ring
• Acidity of phenols


  Weakly acidic due to the presence of the hydroxyl group. The hydroxyl group can donate a proton (H⁺ ion) in solution, making phenols slightly acidic. However, they are generally less acidic than carboxylic acids.
• Phenols


  • Often have distinctive odors
  • Commonly found in aromatic substances such as essential oils
• Phenol substitution reactions


  1. Hydroxyl group is replaced by another functional group

  2. Common reactions include halogenation, nitration, and sulfonation
• Phenol esterification reactions


  Reaction with carboxylic acids to form esters
• Phenols


  Can form hydrogen bonds with other molecules due to the presence of the hydroxyl group, influencing their solubility and boiling points
• (LiAlH4) is commonly used to reduce:

  • Carbonyl compounds (aldehydes, ketones)
  • Carboxylic acids
  • Esters
  • Amides
  • Acid chlorides
  • Epoxides
• 1. Lithium (Li+): Crimson red
  2. Sodium (Na+): Yellow
  3. Potassium (K+): Lilac
  4. Calcium (Ca2+): Brick red (Orange-red)
  5. Barium (Ba2+): Pale green or apple green
  6. Strontium (Sr2+): Crimson red (similar to lithium but darker)
  7. Copper (Cu2+): Blue or green, depending on the oxidation state
  8. Lead (Pb2+): Bluish-white (may be difficult to see in a normal flame)
  9. Selenium (Se2-): Pale blue (non-metal)
• Any half-cell that has a positive value when connected to the SHE undergoes reduction and so contains a species which is an oxidising agent towards H+ ions .
• Any half-cell that has a negative value when connected to the SHE undergoes oxidation and so contains a species which is a reducing agent towards H2 molecules.
• • EMF- most positive - most negative