Names and Formulae of Common Cations and Anions

Vocabulary flashcards covering the definitions, formulas, charges, and naming rules for common cations and anions based on the lecture notes.

Cation

An ion with a positive charge, typically formed by Group I to Group III elements. Ions with a charge of $4+$ are uncommon.

Anion

An ion with a negative charge, typically formed by Group V to Group VII elements. Ions with a charge of $4-$ are uncommon.

Ammonium ion

A non-metal cation with the formula $NH_4^+$, which is the only common polyatomic cation.

Non-metal Cations

Cations formed from non-metals, specifically hydrogen ion ($H^+$) and ammonium ion ($NH_4^+$).

Single-Charge Metal Cation Naming

The rule stating that if a metal forms only one cation, the ion has the same name as the metal (e.g., sodium metal $Na$ forms sodium ion $Na^+$).

Variable-Charge Metal Cation Naming

The rule stating that when transition metals form multiple cations, a Roman numeral indicating the charge is written in brackets after the metal name (e.g., iron(II) ion $Fe^{2+}$ and iron(III) ion $Fe^{3+}$).

Simple Anion Naming Rule

The rule stating that simple anions formed from non-metals end in the suffix '-ide' (e.g., oxygen atom $O$ forms oxide ion $O^{2-}$, sulphur atom $S$ forms sulphide ion $S^{2-}$).

Polyatomic Oxyanion Naming Rule

The rule stating that oxygen-containing polyatomic anions with more oxygen atoms end in '-ate' (e.g., sulphate ion $SO_4^{2-}$) and those with less oxygen end in '-ite' (e.g., sulphite ion $SO_3^{2-}$).

Hydrogencarbonate ion

A polyatomic anion with the formula $HCO_3^-$ and a charge of $1-$.

Hydrogensulphate ion

A polyatomic anion with the formula $HSO_4^-$ and a charge of $1-$.

Permanganate ion

A polyatomic anion composed of a metal and non-metal with the formula $MnO_4^-$ and a charge of $1-$.

Dichromate ion

A polyatomic anion composed of a metal and non-metal with the formula $Cr_2O_7^{2-}$ and a charge of $2-$.

Thiosulphate ion

A polyatomic anion with the formula $S_2O_3^{2-}$ and a charge of $2-$.

Chlorate ion

A polyatomic anion with the formula $ClO_3^-$ and a charge of $1-$.

Hypochlorite ion

A polyatomic anion with the formula $ClO^-$ and a charge of $1-$.

Phosphate ion

A polyatomic anion with the formula $PO_4^{3-}$ and a charge of $3-$.

Nitride ion

A simple non-metal anion with the formula $N^{3-}$ and a charge of $3-$.

Phosphide ion

A simple non-metal anion with the formula $P^{3-}$ and a charge of $3-$.