Assigning Oxidation Numbers

Front

What is an oxidation number?

Back

The oxidation number is a value that represents the total number of electrons an atom either gains or loses when it forms a chemical bond.

Front

What is the oxidation number of oxygen in most compounds?

Back

-2

Front

What is the oxidation number of hydrogen in most compounds?

Back

+1

Front

What is the oxidation number of alkali metals in compounds?

Back

+1

Front

What is the oxidation number of alkaline earth metals in compounds?

Back

+2

Front

What is the oxidation number of halogens in compounds?

Back

Typically -1, unless combined with oxygen or other halogens.

Front

How do you determine the oxidation number of an element in a compound?

Back

By using known oxidation states of other elements in the compound and applying the rule that the sum of oxidation numbers in a neutral compound is zero.

Front

What is the oxidation number of sulfur in SO4^2-?

Back

+6

Front

What is the oxidation number of carbon in CH4?

Back

-4

Front

What is the oxidation number of chromium in Cr2O7^2-?

Back

+6