Question

Would you expect powdered solid aluminium to act as an oxidizing agent or as a reducing agent?

Short answer

Aluminium has a negative standard reduction potential across both acidic and basic media, indicating that it functions as a reducing agent.

Step-by-step solution

Definition of oxidizing and reducing agent.

Oxidizing agent: In a chemical reaction, oxidising agents are molecules that gain electrons.

Reducing agent: A material that can lose electrons is referred to as a reducing agent.

Explanation of solution.

Consider the equations,

${\text{E}}^{\text{o}}\left({\text{Al}}^{\text{3+}}\mid \text{Al}\right)\text{=-1.66V}$ In acidic medium.

${\text{E}}^{\text{o}}\left({\text{Al(OH)}}_{\text{4}}^{\text{-}}\mid \text{Al}\right)\text{=-2.34V}$ In basic medium.

Thus, as a result aluminium has a negative standard reduction potential in both acidic and basic environments, indicating that it reduces.