Strong and Weak Acids, Bases, and Neutral Ions

A set of vocabulary flashcards covering the definitions, formulas, and classifications of strong and weak acids, strong and weak bases, conjugate acid-base strength trends, and neutral ions.

Monoprotic Acid

An acid that contains one ionizable proton ($1$ hydrogen that can break off).

Diprotic Acid

An acid that contains two ionizable protons ($2$ hydrogens that can break off).

Triprotic Acid

An acid that contains three ionizable protons ($3$ hydrogens that can break off).

Seven Strong Acids

The seven strong acids required to memorize: $HCl$ (hydrochloric acid), $HBr$ (hydrobromic acid), $HI$ (hydroiodic acid), $HNO_3$ (nitric acid), $HClO_3$ (chloric acid), $HClO_4$ (perchloric acid), and $H_2SO_4$ (sulfuric acid).

Common Weak Acids

Acids that do not completely ionize in solution, including $HF$ (hydrofluoric acid), $HC_2H_3O_2$ (acetic acid), $HCHO_2$ (formic acid), $H_2SO_3$ (sulfurous acid), $H_2CO_3$ (carbonic acid), $H_3PO_4$ (phosphoric acid), and carboxylic acids.

Strong Bases

Bases that completely dissociate in aqueous solution.

Weak Bases

Bases that partially dissociate in aqueous solution.

Six Strong Bases

The six strong bases required to memorize: $LiOH$, $NaOH$, $KOH$, $Ca(OH)_2$, $Sr(OH)_2$, and $Ba(OH)_2$.

Common Weak Bases

Bases that partially dissociate in solution, including $NH_3$ (ammonia), $CH_3NH_2$ (methylamine), $C_2H_5NH_2$ (ethylamine), $C_6H_5NH_2$ (aniline), and $C_5H_5N$ (pyridine).

Base and Conjugate Acid Strength Relationship

An inverse relationship where a stronger base has a weaker conjugate acid, and a weaker base has a stronger conjugate acid.

Neutral Ions

Ions that do not react with water and therefore maintain a neutral $pH = 7$.

Neutral Cations

Cations derived from strong bases that do not react with water: $Li^+$, $Na^+$, $K^+$, $Ca^{2+}$, $Sr^{2+}$, and $Ba^{2+}$.

Neutral Anions

Anions derived from strong monoprotic acids that do not react with water: $Cl^-$, $Br^-$, $I^-$, $NO_3^-$, $ClO_4^-$, and $ClO_3^-$.