Which one of the following has a potential greater than zero?
Pt, $\frac{1}{2} \text{H}_2$ (1 atm) | $\text{HCl}$ (1 M)
Pt, $\frac{1}{2} \text{H}_2$ (1 atm) | $\text{HCl}$ (2 M)
Pt, $\frac{1}{2} \text{H}_2$ (1 atm) | $\text{HCl}$ (0.1 M)
Pt, $\frac{1}{2} \text{H}_2$ (1 atm) | $\text{HCl}$ (0.5 M)
