Step-by-step explanation:
To find out if it is a redox reaction, we need to know the oxidation number of each element.
The oxidation number (NOX) of an element is the electrical charge it acquires when it forms an ionic bond or the partial character (δ) it acquires when it forms a predominantly covalent bond.
Some NOX rules:
The NOX of simple substances is always zero.
The NOX of ions is equal to their charge.
The sum of the NOX elements of a compound always equals zero.
The sum of the NOXs of the elements in a composite ion is always equal to the charge on the ion.
the Nox of oxygen is almost always -2. However, in the case of the hydrogen peroxide molecule, the Nox of oxygen is -1
the Nox of hydrogen is almost always +1.
Let's calculate the nox of each element on both sides of the reaction:
PbS(s) + O2(g) --> PbO(s) + SO2(g)
Reactants:
PbS:
Pb = +2
S = -2
O2:
O = 0
Products:
Pb = +2
O = -2
SO2:
S = +4
O = -2
Answer:
Oxidized = S
Reduced = O
Oxidizing agent = O2
Reducing agent = PbS