18.1.2 Basicity of Amines

• Amines contain a nitrogen atom with a lone pair of electrons
• Rank the basicity of primary, secondary, and tertiary amines from most to least basic:

  1️⃣ Tertiary Amine

  2️⃣ Secondary Amine

  3️⃣ Primary Amine
• What is the key chemical feature of the nitrogen atom in amines?

  Lone pair of electrons
• What is the defining feature of amines in terms of their structure?

  Nitrogen atom with lone pair
• Why is the lone pair of electrons on the nitrogen atom in amines important?

  Basicity and reactivity
• Why are primary amines the least basic among the three types of amines?

  Hydrogen atoms reduce lone pair
• What two factors influence the basicity of amines?

  Alkyl groups and hydrogen atoms
• Aliphatic amines are more basic than aromatic amines.


  True
• Amines act as bases by accepting protons to form positively charged ammonium
• Amine-based compounds are used as corrosion inhibitors due to their basicity forming protective coatings
• Match the type of amine with its example:

  Primary Amine ↔️ Methylamine (CH3NH2)

  Secondary Amine ↔️ Dimethylamine ((CH3)2NH)

  Tertiary Amine ↔️ Trimethylamine ((CH3)3N)
• The basicity of an amine is determined by the lone pair on the nitrogen atom.


  True
• The lone pair of electrons on the nitrogen atom in amines is crucial for their chemical properties.

  True
• The lone pair on nitrogen attracts H+ ions from strong acids
• Match the type of amine with its general structure:

  Primary Amine ↔️ R-NH₂

  Secondary Amine ↔️ R-NH-R'

  Tertiary Amine ↔️ R-N-R'R''
• The basicity of an amine refers to its ability to accept a proton
• The basicity of amines arises from the nitrogen atom's lone pair accepting a proton
• Match the effect on basicity with its cause:

  Alkyl Groups ↔️ Stabilize positive charge

  Hydrogen Atoms ↔️ Reduce lone pair availability
• Why are aromatic amines less basic than aliphatic amines?

  Lone pair delocalized into ring
• The basicity of amines is crucial for their pharmacological activity in pharmaceuticals.

  True
• What is the key structural feature of amines?

  Nitrogen atom
• What determines the basicity of an amine?

  Ability to accept a proton
• Tertiary amines are the most basic because they have the most accessible lone pair
• What ion is formed when an amine accepts a proton?

  Ammonium ion
• Match the factor affecting basicity with its effect:

  Alkyl Groups ↔️ Increase basicity

  Hydrogen Atoms ↔️ Decrease basicity
• Tertiary amines are the most basic type of amine.


  True
• Alkyl groups stabilize the positive charge on the ammonium ion, increasing basicity.

  True
• Order the three types of amines from most basic to least basic:

  1️⃣ Tertiary Amines

  2️⃣ Secondary Amines

  3️⃣ Primary Amines
• Match the type of amine with its basicity and structure:

  Aliphatic ↔️ More basic, R-NH₂

  Aromatic ↔️ Less basic, Ar-NH₂
• What role do aromatic amines play in the synthesis of dyes and pigments?

  Precursors