Determine the oxidation number(oxidation state) of each element in the three compounds.

Question

Determine the oxidation number(oxidation state) of each element in the three compounds.

1. CuCO₃

_Cu:

_C:

_O:

1. NH₄Cl

N:

H:

Cl:

1. (NH₄)₂CrO₄

_N:

_H:

_Cr:

_O:

Answer 1

.

1. CuCO₃

CO₃ has an overall charge of –2, so Cu has a charge of +2

each O atom has an oxidation number of –2, so C has an oxidation number of +4

Cu: +2

C: +4

O: –2

1. NH₄Cl

Cl has a charge of –1, each H atom has an oxidation number of +1,

so N has an oxidation number of –3

N: –3

H: +1

Cl: –1

1. (NH₄)₂CrO₄

NH₄ has an overall charge of +1, so CrO₄ has an overall charge of –2

each O atom has an oxidation number of –2, so Cr has an oxidation number of +6

N: –3

H: +1

Cr: +6

O: –2