Standard Reduction Potential

Question

Use the Standard Reduction Potential table and assume standard conditions.

a.) Is H+(aq) capable of oxidizing Cu (s) to Cu+2 (aq)?

b.) Is H2 (g) capable of reducing Ag+ (aq)

Answer 1

Here's what you gotta know about Reduction Potentials.

The LARGER the "Reduction Potential" the more likely it is that that reduction reaction will happen; i.e., the more likely that substance will be reduced.; i.e, the more likely that substance will be the one to accept the electrons (as opposed to being the substance that gives up electrons/be oxidized).

So in these questions....

a) we want to know if H+ will accept the electrons from Cu (s) which will be oxidized to Cu2+.

The reduction potential of Cu2+ to Cu(s) is +0.34

The reduction potential of H+ to H2 is 0

Which of these has the LARGER reduction potential?

Cu2+

Therefore Cu2+ is more likely to be reduced than H+.

So ,Cu 2+ will go to Cu(s) while H2 goes to H+ BUT NOT THE OTHER WAY AROUND. [ Cu(s) does not go to Cu2+ while H+ goes to H2, which means that Cu(s) cannot be oxidized by H+)

No, H+ cannot oxidize Cu(s)

b) Reduction potential of Ag+ to Ag (s) is 0.8

Reduction potential of H+ to H2 is 0

Reduction potential of Ag+ is larger than the reduction potential of H+.

Therefore, Ag + to Ag (s) is more likely to happen than H+ to H2.

That is, Ag+ will go to Ag (s) while H2 goes to H+ BUT NOT THE OTHER WAY AROUND. [Ag (s) will not be oxidized to Ag+ while H+ is reduced to H2)

So, Yes, H2 can reduce Ag+ to Ag (s)