Finding Oxidation Numbers

What are the 2 ways oxidation numbers can be found?

Formulas and systematic names

Example: find the oxidation number of Zn in Zn(OH)2?

Zn(OH)2 is neutral so its oxidation number is 0. Oxidation number of (OH)2 is 2(-2+1)=-2 so Zn has to be +2

What happens if an element can have multiple oxidation numbers or isn't in its oxidation state?

It's oxidation number can be shown by using Roman numerals

Where are the Roman numerals written?

After the name of the element they correspond to.

How would iron (ii) sulfate look like?

FeSO4

What would iron (iii) sulfate look like?

Fe2(SO4)3

What do ions with names ending in -ate contain?

Oxygen and another element

What can the element in the -ate ion be?

Different oxidation numbers and form different -ate ions

What will happen in sulfate (vi) ions?

Sulfur has oxidation number +6 so is SO4 2- ion

What will happen in sulfate (IV) ions?

Sulfur has oxidation number +4 so is SO3 2- ion

What will happen in nitrate (iii)?

Nitrogen har oxidation number +3 so is NO2 - ion