Provide an example of a half-cell reaction and redox equation.

Half-cell reactions involve the transfer of electrons between species.

An example of a half-cell reaction is the oxidation of zinc metal to form zinc ions. This can be represented as follows:

Zn(s) → Zn2+(aq) + 2e-

In this reaction, the zinc metal loses two electrons to form positively charged zinc ions. The electrons are released into the solution and can be used to reduce another species.

A redox equation involves the combination of two half-cell reactions, one oxidation and one reduction. An example of a redox equation is the reaction between zinc metal and copper ions to form copper metal and zinc ions. This can be represented as follows:

Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s)

In this reaction, the zinc metal is oxidized to form zinc ions, while the copper ions are reduced to form copper metal. The electrons released from the zinc half-reaction are used to reduce the copper ions in the other half-reaction.

Redox reactions are important in biological systems, as they are involved in energy production and the transfer of electrons in metabolic pathways. Understanding half-cell reactions and redox equations is therefore crucial for understanding these processes.