How are polyatomic ions named?

2 Answers
Aug 4, 2018

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"#...

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 = # 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.