The standard cell potential (E°) of a voltaic cell constructed using the cell reaction below is 0.76 V:
Zn(s) + 2 H+(aq) → Zn2+(aq) + H2(g)
With PH2 = 1.0 atm and [Zn2+] = 1.0 mol L-1, the cell potential is 0.66 V. The concentration of H+(aq) in the cathode compartment is ________ mol L-1.
◦ 2.0 × 10-2
◦ 4.2 × 10-4
◦ 1.4 × 10-1
◦ 4.9 × 101
◦ 1.0 × 10-12