Oxidation Numbers

Exam 3, Chem 115, WVU fall '25

Free elements (ie. C, Mg, O₂) always have an oxidation number of __

zero (f)

In a neutral compound, all the oxidation atoms must add up to __

0

In an ion, all the oxidation elements must add up to __

the ion’s charge

Fluorine has an ON of __

-1 (f)

Group 1 has an ON of __

+1 (g)

Group 2 has an ON of __

+2 (g)

Hydrogen (with metals or boron) has an ON of __

-1 (h)

Hydrogen (with nonmetals) has an ON of

+1 (h)

Oxygen (except with fluorine or peroxides) has an ON of __

-2 (o)

Group 7A has an ON of __ except when combined with another element of higher electronegativity

-1 (g)

Group 6A has an ON of __

-2 (g)

Group 5A has an ON of __ (ONLY applies to N and P)

-3 (g)

Oxidation numbers are ___ to ionic charges

not equivalent

The __ is typically written first in a chemical formula

cation

If oxygen is in a peroxide, its ON is __

-1 (p)

If oxygen is bonded to fluorine, its oxidation number is __

+1 (o)