Question

Find the oxidation numbersi) Oxidation number of Pb in PbOj) Oxidation number of O in PbOk) Oxidation number of Pb in PbO2l) Oxidation number of O in PbO2

Answer 1

The oxidation number of Pb in PbO is +2 and in PbO2 is +4. Oxygen has an oxidation number of -2 in both compounds.

Step-by-step explanation:

To determine the oxidation numbers for lead (Pb) and oxygen (O) in the compounds PbO and PbO2, the following rules can be applied:

1. The oxidation number of oxygen is generally -2 in its compounds.
2. The sum of oxidation numbers in a neutral compound is zero.

For PbO:

• Let the oxidation number of Pb be x.
• Oxygen's oxidation number is -2.
• x + (-2) = 0 (since the compound is neutral)
• x = +2

Therefore, the oxidation number of Pb in PbO is +2, and of O is -2.

For PbO2:

• Let the oxidation number of Pb be x.
• There are two oxygens, so 2(-2)
• x + 2(-2) = 0
• x - 4 = 0
• x = +4

Hence, the oxidation number of Pb in PbO2 is +4, and of O is -2.

Answer 2

i) The oxidation number of Pb in PbO is +2.

j) The oxidation number of O in PbO is -2.

k) The oxidation number of Pb in PbO2 is +4.

l) The oxidation number of O in PbO2 is -2.

Explanation:

j) We can start from Oxygen since its oxidation number is alway -2 (except in peroxides where it is -1).

i) As we can see the molecule of PbO is neutral, so knowing that Oxygen has an oxidation number of -2, Pb will have an oxidation number of +2 to make the molecule neutral.

l) We can also start with oxygen for PbO2 molecule, as the same in PbO, O has an oxidation number of -2.

k) PbO2 is also a neutral molecule, but in this case, there are 2 Oxygens with oxidation number of -2, so the total negative charge is -4 ((-2)*2), so to make the whole molecule neutral, Pb must have an oxidation number of +4.