Question

How are polyatomic ions named?

Answer 1

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

Explanation:

And thus...

`NO_3^(-)-="nitrate"`

`NO_2^(-)-="nitrite"`

`SO_4^(2-)-="sulfate"`

`HSO_4^(-)-="bisulfate"`

`SO_3^(2-)-="sulfite"`

`ClO_4^(-)-="perchlorate, Cl(+VII)"`

`ClO_3^(-)-="chlorate, Cl(+V)"`

`ClO_2^(-)-="chlorite, , Cl(+III)"`

`ClO^(-)-="hypochlorite, , Cl(+I)"`

`HPO_4^(2-)-="biphosphate"`

`NO_3^(-)-="nitrate"`

`MnO_4^(-)-="permanganate"`...

Clearly, this is a selection....the ions that have the central atom in its maximum oxidation state, i.e. `SO_4^(2-)`, `HPO_4^(2-)`, get an `"ate"` ending...`"ite"` endings refer to a LOWER oxidation state, cf. `SO_3^(2-)`, `"sulfite"`...

Answer 2

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 = `NO_3^-1` the normal oxidation state for Nitrogen is +5
sulfate =`SO_4^-2` the normal oxidation state for sulfate is +6
Chlorate=`ClO_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 = `NO_2^-1` the oxidation state is + 3 < +5
Sulfite=`SO_3^-2` the oxidation state is + 4 < + 6
Chlorite=`ClO_2^-1` the oxidation state is +3 < + 5

Hyper ate means the oxidation state is more than normal

Hyper Chlorate = `ClO_4^-1` the oxidation is + 7 > +5

Hypo its means the oxidation state is less than normal

HypoChlorite = `ClO^-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.