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To write the name of oxygen-containing acid one must be able to calculate the

oxidation state of the acid-forming element. To do this it should be taken into

account that the oxidation state of Hydrogen is +1, the oxidation state of Oxygen is

-2, and the molecule is generally electroneutral. For example, to determine the

oxidation state of Sulfur in H 2SO 4 it is necessary to add oxidation state of

Hydrogen and Oxygen, taking into account the number of their atoms 2·(+ 1) +

4·(–2) = –6, and get the received number with the opposite sign. Then Sulfurous

oxidation state in H 2SO 4 is +6.

To determine the oxidation state of Phosphorus in H 4Р 2O 7 it is necessary to add

oxidation state of Hydrogen and Oxygen, taking into account the number of their

atoms

4 • (+ 1) + 7 • (-2) = -10.

and get the resulting number with the opposite sign, and divide it by the number of
Phosphorus atoms (2). Then the oxidation state of phosphorus in H 4Р 2O 7 is + 10/2

= + 5.

1. If the acid-forming element evinces only one the oxidation state in acids,

then the suffix “-ic” is added to the root of the Latin name of the corresponding

element in the names of oxygen-containing acids.
+4
For example: C , H 2СO 3 - carbonic acid.

2. If the element is capable of evincing two oxidation states, then for the higher

the oxidation state in the name of the acid the suffix “-ic” is used, and for the lower
+5
+3
+4
one – “-ous”. For example: N , HNO 2- nitrous acid, N , HNO 3 - nitric acid, S ,
+6
H 2SO 3 - sulfurous acid, S , H 2SO 4 - sulfuric acid
3 If an element is capable of evincing a greater number of oxidationstates, then

to the Latin root of element name is added:

• at the lowest oxidation state the prefix “hypo- and the suffix “-ous”,

• at a slightly higher oxidation state the “-ous” suffix,

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