In: Chemistry
Given:
Pb2+(aq)+2e–⇌Pb(s);E°=–0.13
Mg2+(aq)+2e–⇌Mg(s);E°=–2.38V
Ag+(aq)+e–⇌Ag(s);E°=0.80V
2H+(aq)+2e–⇌ H2(g);E°=0.00V
Under standard-state conditions, which of the following species is the best oxidizing agent?
a. H
b.Mg2+
c. Ag+
d. Pb
e. Ag
Ans. Reduction potential (redox potential) of a chemical species is its ability to accept electrons from another chemical species. Greater is the reduction potential, higher would be the ability to accept electrons, i.e. the chemical species can draw/accept electrons more easily.
Note the following point-
I. The more positive is the standard redox potential, higher is the value of redox potential.
II. The higher is the redox potential of a chemical species (A), more it would draw/accept electrons from other chemical species (B).
III. The more easily A draws electrons B, the more easily be B oxidized (loss of electrons is species). Since A oxidizes B, A is the oxidizing agent.
# Therefore, the more positive is redox potential of a chemical species, the better would it be an oxidizing agent.
# Among the available options, the standard redox potential of Ag+ is highest + 0.80V. So, Ag+ is the best oxidizing agent.
Hence, correct option is c. Ag+