Question

What is the standard cell notation for a galvanic cell made with silver and nickel?

Answer 1

Answer:

Ni(s)∣∣Ni2+(aq) ∣∣∣∣ Ag+(aq)∣∣Ag(s)

Explanation:

Start by finding the standard reduction potential for the Ag+ and Ni2+ ion. Normally, the values are listed at the back of most chemistry textbooks.

Ag+(aq)+1e−→Ag(s) Eo=0.80 V
Ni2+(aq)+2e−→Ni(s) Eo=−0.23 V

In the galvanic cell, the reaction is spontaneous and for a spontaneous reaction Eocellmust be a positive quantity.

Eocell=EoAnode+Eocathode

Manipulate the two equations so that Eocell is positive. Note that the anode is the site of oxidation (where electrons are lost) and the cathode (where electron are gained) is the site for reduction.

Ag+(aq)+1e−→Ag(s) Eo=0.80 V
Ni(s)→Ni2+(aq)+2e− Eo=0.23 V

2×{Ag+(aq)+1e−→Ag(s)} Eo=0.80 V (Cathode)
Ni(s)→Ni2+(aq)+2e− Eo=0.23 V (Anode)
−−−
2Ag+(aq)+Ni(s)→Ni2+(aq)+2Ag(s) Eocell=1.03 V

Start with the anode components (site of oxidation) - the cathode components are listed to the right.

Ni(s)∣∣Ni2+(aq) ∣∣∣∣ Ag+(aq)∣∣Ag(s)

The single vertical lines indicate the boundary (phase difference) between solid Niand Ni2+ ions in the aqueous solution of the first compartment and between solid Ag and Ag+ ions present in the aqueous solution of the second compartments.

The double vertical lines refer to the salt bridge - note that the salt bridge must be an inert salt to both ions present in both compartments of the galvanic cell ...