Answer:
correct answer is (A) AgNO3 (aq).
Step-by-step explanation:
Metal Plating in Solutions
Nehal Kafle
A 2.0 A current is applied to beakers containing identical volumes of each of the following 1.0 M solutions. In beaker will the greatest mass of metal plate out? (A) AgNO3 (aq) (B) CuSO4 (aq) (C) FeCl2 (aq) (D) AlBr3 (aq)
The metal that plates out will be the one that has the highest reduction potential among the metals present in the solution. We can determine this by consulting a table of standard reduction potentials. Here are the reduction half-reactions for the four metal ions:
(A) Ag+ + e- → Ag E° = +0.80 V
(B) Cu2+ + 2e- → Cu E° = +0.34 V
(C) Fe2+ + 2e- → Fe E° = -0.44 V
(D) Al3+ + 3e- → Al E° = -1.66 V
The greater the reduction potential, the easier it is for the metal to gain electrons and be reduced to its elemental form. Thus, the metal with the highest reduction potential will plate out first.
Comparing the reduction potentials of the four metals, we see that Ag+ has the highest reduction potential (+0.80 V), followed by Cu2+ (+0.34 V), Fe2+ (-0.44 V), and Al3+ (-1.66 V). Therefore, the solution with AgNO3 will have the greatest mass of metal plating out.
Therefore, the correct answer is (A) AgNO3 (aq).