What is the standard electrode potential of a Daniell cell (in $V$)?

For the cell reaction $Mg_{(s)} + Zn^{2+}_{(aq)} (1M) \rightarrow Zn_{(s)} + Mg^{2+}_{(aq)} (1M)$,the $emf$ is $1.60 \ V$. The $E$ of the cell is ........ $V$.

The $EMF$ of the cell $Ni | Ni^{2+} (1.0 \ M) || Au^{3+} (1.0 \ M) | Au$ is ............ $V$. (Given: $E^o_{Ni^{2+}/Ni} = -0.25 \ V$; $E^o_{Au^{3+}/Au} = 1.50 \ V$)

For the cell involving the following reaction: $Zn_{(s)} + Ni^{2+}_{(aq)} \longrightarrow Zn^{2+}_{(aq)} + Ni_{(s)}$. Given $E^{\circ}_{\text{cell}} = 0.5 \ V$. What is the standard Gibbs energy change of the cell reaction (in $kJ$)?

Which of the following has the least tendency to liberate $H_2$ from mineral acids?

For the spontaneity of a cell,which of the following is correct?