pKa Values of Functional Groups Flashcards

Study Notes

pKa Values of Functional Groups

Protonated Carbonyl: pKa of -7, indicates strong acidity.
Protonated Alcohol or Ether: pKa range of -2 to -3, showcasing moderate acidity.
Carboxylic Acid: Exhibits a pKa of 4 to 5, representing weak acid behavior.
Ammonium Ion: pKa falls between 9 to 10, displaying its role as a weak base.
Phenol: Acidity characterized by a pKa of 10, revealing aromatic stability.
Thiol: Also has a pKa of 10, highlighting its comparable acidity to phenols.
Alcohol: pKa range of 16 to 18, pointing to weak acidity.
Water: Displays a pKa of 15.7, underscoring its neutral acidity.
Amide: pKa of 18, representing weakly acidic nature due to resonance.
Alpha Proton of Ketone/Aldehyde: pKa of 20, indicating weak acidity associated with carbonyls.
Alpha Proton of Ester: pKa is 25, reflecting low acidity.
Terminal Alkyne: Features a pKa of 25, showing weak acidity similar to esters.
Amine: Demonstrates a pKa range of 38 to 40, indicating very weak acidity.
Aromatic (Aryl): pKa of 43, showcasing minimal acidity in aromatic rings.
Aromatic (Benzylic): pKa of 41, slightly more acidic than aryl compounds.
Alkene (Vinyl): Displays a wide pKa range of 45 to 50, indicating very weak acidity.
Alkene (Allylic): Has a pKa of 43, similarly showing weak acidity.
Alkane: Exhibits pKa values above 50, classifying them as practically non-acidic.
HCl: Strong acid with a pKa of -7.
HBr: Exhibits a pKa of -8, characterizing it as a strong acid.
HI: pKa of -9, reinforcing its strength as a strong acid.
H2SO4: Strong acid with a pKa of -9, similar to HI.

Description

This quiz covers the pKa values of various functional groups, providing essential information for organic chemistry. Test your knowledge on the acidity of compounds such as carboxylic acids, alcohols, and phenols. Perfect for students preparing for exams in organic chemistry or related fields.