In a certain experiment, with chemical equation Zn(s) + H+

(aq) → Zn2+(aq) +
H2(g), the emf (E) of the cell is found to be 0.45 V at 25°C. Suppose that [Zn2+]
= .8 M and PH2 = 1.0 atm. Calculate the molar concentration of H+
.