Silver will spontaneously reduce which of the following?
Reaction E (volts)
Na+ + e- ---> Na -2.71
Co2+ + 2e- ---> Co -0.28
Ag+ + e- ---> Ag .80
A) Na
B) Co2+
C) Na+
D)Co
E) None of these
none of these.
Please explain why
Here is a link for the activity series (they are written as oxidations and not reductions). Any metal ABOVE an ion will displace that ion from solution but will not displace any ion ABOVE IT.
http://www.files.chem.vt.edu/RVGS/ACT/notes/activity_series.html
Therefore, Na + Ag^+ ==> Ag + Na^+ BUT
Na^+ + Ag ==> No reaction.
You can do it another way by writing half reactions and see which will give you a positive voltage.
Ag ==> Ag^+ + e Eo = -0.8
Na^+ + e ==> Na Eo = -2.71
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Ag + Na^+ ==> Ag^+ + Na
and Eocell = -3.something and negative voltages are not spontaneous.
Ag ==> Ag^+ + e Eo = -0.8
Co^2+ + 2e ==> Co Eo = -.28
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2Ag + Co^2+ ==> 2Ag^+ + Co
and Eocell = -1.something. Negative. not spontaneous.
Ag ==> Ag^+ + e Eo = -0.80
Na ==> Na^+ + e Eo = 2.71
BUT this is not a reaction because BOTH reactions are oxidations. You must have one oxidation half cell and one reduction half cell to get a cell. Both can't be oxidations and both can't be reductions.
compare the e values with silver and i think you will see why...
But the given Ecell for Ag was positive .80 why did you use -.80? And how do you know that Na+ is a reduction?
Ag^+ + e = Ag is given in the table as 0.80 but I wrote it as
Ag ==> Ag^+ +e therefore, I changed the sign.
For the second part of your question, answer A is Na and answer C is Na^+. I used both of them. If you start with Na it MUST go to Na^+ and if you start with Na^+ it MUST go to Na.
To determine which substance silver will spontaneously reduce, we need to compare the reduction potentials (E) of each species involved in the reactions. The reduction potential is a measure of the tendency of a species to gain electrons and undergo reduction.
In this case, we have three reactions involving the reduction of sodium ions (Na+), cobalt ions (Co2+), and silver ions (Ag+). The reduction potentials are given for each reaction.
The reaction with the highest reduction potential is Ag+ + e- → Ag, which has an E value of 0.80 volts. A positive reduction potential indicates that the reduction is thermodynamically favored.
Comparing this with the reduction potentials of Na+ and Co2+, we can see that -2.71 volts and -0.28 volts, respectively, are lower than 0.80 volts. This means that both Na+ and Co2+ have lower tendencies to undergo reduction compared to Ag+.
Therefore, the answer is E) None of these. Silver (Ag) will not spontaneously reduce any of the given substances, including Na+, Co2+, Na+, and Co.