To determine the voltage of a galvanic cell made with silver and nickel, we need to consult the standard reduction potentials for each metal. The standard reduction potential is a measure of the tendency of a substance to undergo reduction, with more positive values indicating a greater tendency to be reduced.

The standard reduction potentials for silver and nickel are:

Ag+ + e- → Ag E° = +0.80 V

Ni2+ + 2e- → Ni E° = -0.25 V

In a galvanic cell, the anode is the electrode where oxidation occurs, and the cathode is the electrode where reduction occurs. In this case, silver will be oxidized (since it has a more positive reduction potential), and nickel will be reduced.

The overall cell reaction is:

Ag(s) + Ni2+(aq) → Ag+(aq) + Ni(s)

To calculate the cell voltage, we subtract the standard reduction potential of the anode from the standard reduction potential of the cathode:

E°cell = E°cathode - E°anode

E°cell = (+0.80 V) - (-0.25 V)

E°cell = +1.05 V

Therefore, the voltage of the galvanic cell made with silver and nickel is +1.05 V.