Inorganic and Applied Chemistry

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Inorganic and Applied Chemistry

Example 6- A:

Assigning levels of oxidation

We are to assign levels of oxidation to all atoms in the following compounds:

CO 2 , H 2 SO 4 , NO 3 - and HF

Levels of oxidations in CO 2 :

Form the rules on the above we have that each oxygen atom is assigned the oxidation level of -2. the

oxidation step for C may thereby be determined on the basis of this and the fact that CO 2 does not have

any external charge which is why the sum of oxidation levels should be zero. Thus, C in CO 2 has a level of

oxidation of +4.

Levels of oxidations in H 2 SO 4 :

Based on the rules earlier stated we have shown that the oxygen atom is given a level of -2 while the

hydrogen atom is given a level of +1. The oxidation level for S may thereby be determined on the basis of

this as well as on the basis of the fact that H 2 SO 4 does not have an external charge meaning that the sum of

the oxidation levels must be zero. Hence, S in H 2 SO 4 has the oxidation level of +6

Levels of oxidations in NO 3 - :

Form the rules earlier stated we have that each oxygen atom is assigned the level of oxidation of -2. the

level of oxidation for N may thereby be determined on the basis of this as well as on the fact that NO 3 -

have an external charge of -1 which is why the sum of the oxidation levels must be -1 according to the

rules. Thus, N in NO 3 - has a level of oxidation of +5.

Levels of oxidations in HF:

According to the rules above we have that each hydrogen atom is assigned the level of oxidation of +1. the

level of oxidation for F may be determined on the basis of this as well as the fact that HF does not have an

external charge. Hence, F in HF has the level of oxidation of -1 which also fits with the rule that the most

electronegative component in a compound are assigned the negative level of oxidation as well as that case

that flouring always are assigned a -1 level in chemical compounds.

Electrochemistry