Standard potentials: predicting a redox reaction

$E^\circ(\text{Ox/Red})$ is the potential of the couple, written in the reduction direction $\text{Ox} + n\,\ce{e^-} \rightarrow \text{Red}$, measured against the standard hydrogen electrode (SHE), for which $E^\circ = 0$ V by convention. Standard conditions: activities equal to $1$, pressure of $1$ bar; tables are given at $25\ ^\circ\text{C}$.