. For each of the following unbalanced oxidation-reduction chemical equations, balance the equation by inspection, and identify which species is the reducing agent.

a. Fe ( s ) + O 2 ( g ) → Fe 2 O 3 ( s )    b. Al ( s ) + Cl 2 ( g ) → AlCl 3 ( s )    c. Mg ( s ) + P 4 ( s ) → Mg 3 P 2 ( s )

(a)

Interpretation:

The given oxidation-reduction reaction should be balanced by inspection and reducing agent should be identified.

Concept Introduction:

The oxidation-reduction reaction is also known as a redox reaction. In this reaction, one reactant is oxidized and other is reduced. The balancing of oxidation-reduction reaction can be done by simple method by comparing the number of each atoms on both sides of the reaction arrow without addition of hydrogen ion, water molecule and electrons from outside.

The given reaction is as follows:

Fes+O2g→Fe2O3s

First the given reaction should be balanced. To balance the oxygen atoms, give coefficient 3 to O2 and 2 to Fe2O3 thus,

Fes+3O2g→2Fe2O3s

Now, give coefficient 4 to Fe to balance the number of iron atom thus,

4Fe

(b)

Interpretation:

The given oxidation-reduction reaction should be balanced by inspection and reducing agent should be identified.

Concept Introduction:

The oxidation-reduction reaction is also known as a redox reaction. In this reaction, one reactant is oxidized and other is reduced. The balancing of oxidation-reduction reaction can be done by simple method by comparing the number of each atoms on both sides of the reaction arrow without addition of hydrogen ion, water molecule and electrons from outside.

(c)

Interpretation:

The given oxidation-reduction reaction should be balanced by inspection and reducing agent should be identified.

Concept Introduction:

The oxidation-reduction reaction is also known as a redox reaction. In this reaction, one reactant is oxidized and other is reduced. The balancing of oxidation-reduction reaction can be done by simple method by comparing the number of each atoms on both sides of the reaction arrow without addition of hydrogen ion, water molecule and electrons from outside.