Can somebody help me with this question?
Zinc metal is placed in a solution of copper ions and undergoes an oxidation-reduction reaction. Which direction is the spontaneous reaction?
Zn metal goes into solution. Cu(II) ions come out.
Zn + Cu+2 ==> Zn+2 + Cuo
Zn metal is oxidized. Cu ion is reduced.
To determine the direction of the spontaneous reaction in an oxidation-reduction reaction, you can use the concept of reduction potentials.
First, you need to know the reduction potentials of zinc (Zn) and copper (Cu) half-reactions. The reduction potential measures the tendency of a species to gain electrons and undergo reduction.
Next, compare the reduction potentials of the two half-reactions. The species with a higher reduction potential is more likely to be reduced (undergo reduction), while the species with a lower reduction potential is more likely to be oxidized (undergo oxidation).
In this case, the half-reactions are as follows:
Zn + 2e- --> Zn2+ (reduction half-reaction)
Cu2+ + 2e- --> Cu (oxidation half-reaction)
The standard reduction potentials (E°) for these half-reactions are:
Zn2+/Zn: -0.76V
Cu2+/Cu: +0.34V
Since the reduction potential of copper (Cu2+/Cu) is more positive than that of zinc (Zn2+/Zn), copper is more likely to be reduced, and zinc is more likely to be oxidized.
Therefore, the spontaneous reaction direction is from zinc metal (Zn) into solution (Zn2+) while copper ions (Cu2+) come out of solution and form copper metal (Cu).