OChem: Electronegativity and PKa Vocabulary

VOCABULARY flashcards covering key terms from the notes: electronegativity concepts and common acids/bases used to discuss pKa and acid-base behavior in OChem.

Electronegativity

A measure of an atom's ability to attract electrons in a chemical bond.

Increasing electronegativity

The trend where atoms become more able to attract electron density across a period toward more electronegative elements.

pKa

A logarithmic measure of acid strength ($pKa = -log_{10} Ka$); lower pKa indicates a stronger acid.

HCl

Hydrochloric acid; a strong mineral acid that dissociates completely in water.

pKa of HCl

$pKa \approx -7$ (very strong acid).

H2SO4

Sulfuric acid; a very strong, diprotic acid commonly used as a reference strong acid in OChem.

pKa1 of H2SO4

$pKa1 \approx -3$ (first proton dissociation).

pKa2 of H2SO4

$pKa2 \approx 1.99$ (second proton dissociation).

TsOH

p-Toluenesulfonic acid; a strong organic acid widely used as an acid catalyst in organic synthesis.

pKa of TsOH

$pKa \approx -2.8$.

H2O

Water; an amphiprotic solvent that can act as both an acid and a base in acid–base reactions.

pKa of H2O

$pKa \approx 15.7$ (when acting as an acid).