Question

consider the half reactions below for a chemical reaction.
zn \longrightarrow zn²⁺(aq) + 2e⁻
cu²⁺(aq) + 2e⁻ \longrightarrow cu(s)
what is the overall equation for this chemical reaction?
\circ zn(s)+ cu²⁺(aq) \longrightarrow zn²⁺(aq) + cu(s)
\circ zn(s)+ cu²⁺(aq) \longrightarrow cu²⁺(aq)+ 2e⁻
\circ zn²⁺(aq) + cu(s) \longrightarrow cu²⁺(aq) + zn(s)
\circ zn²⁺(aq)+ 2e⁻ \longrightarrow cu²⁺(aq)+ 2e⁻

Explanation:

Step1: Identify oxidation and reduction half - reactions

The first half - reaction \(Zn
ightarrow Zn^{2 + }(aq)+2e^{-}\) is an oxidation reaction (zinc loses electrons). The second half - reaction \(Cu^{2+}(aq)+2e^{-}
ightarrow Cu(s)\) is a reduction reaction (copper(II) ions gain electrons).

Step2: Combine the two half - reactions

To get the overall reaction, we add the two half - reactions together. When we add \(Zn
ightarrow Zn^{2 + }(aq)+2e^{-}\) and \(Cu^{2+}(aq)+2e^{-}
ightarrow Cu(s)\), the electrons (\(2e^{-}\)) on the product side of the oxidation half - reaction and the reactant side of the reduction half - reaction will cancel out.

Adding the reactants of both half - reactions: \(Zn + Cu^{2+}(aq)\)

Adding the products of both half - reactions: \(Zn^{2+}(aq)+Cu(s)\)

So the overall reaction is \(Zn(s)+Cu^{2+}(aq)
ightarrow Zn^{2+}(aq)+Cu(s)\)

Answer:

A. \(Zn(s)+Cu^{2+}(aq)
ightarrow Zn^{2+}(aq)+Cu(s)\)