Question

Balance the following redox reaction and type the coefficients for each of the species in the balanced reaction.Indicate the reducing agent and the oxidizing agent. (Write the species with charge and slate.) Reducing agent: Oxidizing agent:

Answer 1

We balance this equation by ION-ELECTRON PARTIAL METHOD

Al(s)             = Al³⁺(aq) + 3e    Loss of electron. Hence OXIDATION

F₂(g)   +2e   =   2F^- (aq)                       Gain of electrons. Hence REDUCTION

In a redox reaction, the number of electrons lost in oxidation must be equal to the number of electrons gained in reduction.

Therefore to make the number of eklectrons equal, multiply the oxidation equation by 2 and the reduction equation by 3

2Al(s)            =        2Al³⁺(aq) + 6e  

3F₂(g)   + 6e =   6F^- (aq)              

Adding these two equations we get the REDOX equation

2Al(s) + 3F₂(g)              =        2Al³⁺(aq) + 6F^- (aq)     REDOX EQUATION   

In a redox reaction the substance which undergoes oxidation is the reducing agent (because it is an electron donor) and the substance which undergoes reduction is the oxidizing agent (because it is an electron acceptor)

So Al(s) is the REDUCING AGENT

and F₂(g) is the OXIDIZING AGENT