The standard electrode potential (reduction) of Ag⁺|Ag is 0.800 V at 25°C. Its electrode potential in a solution containing 10^–3 M ion of Ag⁺ ions is

0.623 V

The  given cell can be written as

\(Ag^+  +  1e^-  \rightarrow  Ag\)     \(E^o_{cell} = 0.800 V\)

\(E_{cell}  = E^o_{cell} − \frac{0.0591}{1}log \frac{1}{[Ag^+]}\)

\(E_{cell} = 0.8 − \frac{0.0591}{1}log\frac{1}{10^{−3}}\)

\(E_{cell} = 0.623 V\)