# How are polyatomic ions named?

Aug 4, 2018

Well, usually the characterizing names must simply be learned by usage...

#### Explanation:

And thus...

$N {O}_{3}^{-} \equiv \text{nitrate}$

$N {O}_{2}^{-} \equiv \text{nitrite}$

$S {O}_{4}^{2 -} \equiv \text{sulfate}$

$H S {O}_{4}^{-} \equiv \text{bisulfate}$

$S {O}_{3}^{2 -} \equiv \text{sulfite}$

$C l {O}_{4}^{-} \equiv \text{perchlorate, Cl(+VII)}$

$C l {O}_{3}^{-} \equiv \text{chlorate, Cl(+V)}$

$C l {O}_{2}^{-} \equiv \text{chlorite, , Cl(+III)}$

$C l {O}^{-} \equiv \text{hypochlorite, , Cl(+I)}$

$H P {O}_{4}^{2 -} \equiv \text{biphosphate}$

$N {O}_{3}^{-} \equiv \text{nitrate}$

$M n {O}_{4}^{-} \equiv \text{permanganate}$...

Clearly, this is a selection....the ions that have the central atom in its maximum oxidation state, i.e. $S {O}_{4}^{2 -}$, $H P {O}_{4}^{2 -}$, get an $\text{ate}$ ending...$\text{ite}$ endings refer to a LOWER oxidation state, cf. $S {O}_{3}^{2 -}$, $\text{sulfite}$...

Aug 4, 2018

The endings indicate the degree of oxidation states of the polyatomic ions

#### Explanation:

ate indicates that the ion is oxidized to the normal oxidation state.

nitrate = $N {O}_{3}^{-} 1$ the normal oxidation state for Nitrogen is +5
sulfate =$S {O}_{4}^{-} 2$ the normal oxidation state for sulfate is +6
Chlorate=$C l {O}_{3}^{-} 1$ the normal oxidation state for Cl is +5

ite indicates that the ion is oxidized at less than the normal oxidation state.

nitrite = $N {O}_{2}^{-} 1$ the oxidation state is + 3 < +5
Sulfite=$S {O}_{3}^{-} 2$ the oxidation state is + 4 < + 6
Chlorite=$C l {O}_{2}^{-} 1$ the oxidation state is +3 < + 5

Hyper ate means the oxidation state is more than normal

Hyper Chlorate = $C l {O}_{4}^{-} 1$ the oxidation is + 7 > +5

Hypo its means the oxidation state is less than normal

HypoChlorite = $C l {O}^{-} 1$ the oxidation is + 1 < + 3

Pay attention to the endings of the polyatomic ions. The prefixes and suffixes gives clues of how the polyatomic ions are named.