The reduction potential of a hydrogen half-cell will be positive if:

What is the potential of a half-cell consisting of a zinc electrode in $0.01 \ M$ $ZnSO_4$ solution at $25 \ ^\circ C$ (Given $E^o_{Zn^{2+}/Zn} = -0.763 \ V$) (in $V$)?

Which one of the following will increase the voltage of the cell? $(T = 298 \ K)$ :- $Sn_{(s)} + 2Ag_{(aq)}^{+} \rightarrow Sn_{(aq)}^{2+} + 2Ag_{(s)}$

What is the oxidation potential of $0.05 \, M \, H_2SO_4$ in volts?

The concentration of potassium ions inside a biological cell is at least twenty times higher than the outside. The resulting potential difference across the cell is important in several processes such as transmission of nerve impulses and maintaining the ion balance. $A$ simple model for such a concentration cell involving a metal $M$ is:
$M_{(s)} \mid M^{+}(aq; 0.05 \ M) \parallel M^{+}(aq; 1 \ M) \mid M_{(s)}$
For the above electrolytic cell the magnitude of the cell potential $|E_{cell}|=70 \ mV$.
$1.$ For the above cell
$(A)$ $E_{cell} < 0 ; \Delta G > 0$ $(B)$ $E_{cell} > 0 ; \Delta G < 0$
$(C)$ $E_{cell} < 0 ; \Delta G^{\circ} > 0$ $(D)$ $E_{cell} > 0 ; \Delta G^{\circ} > 0$
$2.$ If the $0.05 \ M$ solution of $M^{+}$ is replaced by $0.0025 \ M$ $M^{+}$ solution,then the magnitude of the cell potential would be
$(A)$ $35 \ mV$ $(B)$ $70 \ mV$ $(C)$ $140 \ mV$ $(D)$ $700 \ mV$
Give the answer for questions $1$ and $2$.

The reduction potential of a hydrogen half-cell will be negative if: