Functional Groups + Amino Acids

• Alkane pKa= ~55-65

  
• Alkyne pKa= ~25

  
• Alkene pKa= ~45

  
• Hydroiodic acid pKa= -10


  HI
• Hydrobromic acid pKa= -9


  HBr
• Hydrochloric acid pKa= -8


  HCl
• Sulfuric acid (H2SO4) pKa= -3

  
• Hydronium ion (H3O+) pKa= -1.7

  
• Sulfonic acids pKa= -1

  
• Hydrofluoric acid pKa= 3.2


  HF
• Carboxylic acid pKa= 4-5

  
• Protonated Amines pKa= 9.5-10.5
• Thiols pKa=~11

  
• Malonates pKa= 9-13

  
• Water pKa= 14


  H2O
• Alcohols pKa= 16-18

  
• Ketone pKa= ~20

  
• Aldehyde pKa= ~24

  
• Nitrile pKa= 25

  
• Ester pKa= 25

  
• Sulfoxide pKa= 31

  
• Amine pKa= ~35

  
• The lower the pKa the stronger the acid.
• The higher the pKa is a weaker acid and produces the strongest conjugate base.
• Benzene Sulfonic acid pKa= -6.5

  
• Carbocation pKa= -7

  
• Conjugate acid of acetic acid pKa= -6

  
• Amide

  
• Nitrate Ion

  
• Ether

  
• Sulfide

  
• Thioester

  
• Phenol pKa= ~10

  
• Imine

  
• Acyl Phosphate

  
• Acyl Halide

  
• Anhydride

  
• Phosphate Ester

  
• Alkyl Halide

  
• Protonated Alcohols pKa = -2