The standard cell potential (E°)of a voltaic cell constructed using the cell reaction below is 0.76 V: Zn(s)+ 2H⁺(aq)→ Zn²⁺(aq)+ H₂(g) With P_H₂ = 1.0 atm and [Zn²⁺] = 1.0 M,the cell potential is 0.66 V.The concentration of H⁺ in the cathode compartment is ________ M.

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The Nernst equation is:E = E° - (RT/nF)lnQwhere:E is the cell potentialE° is the standard cell potentialR is the gas constant (8.314 J/mol·K)T is the temperature in Kelvinn is the number of moles of electrons transferred in the cell reactionF is the Faraday constant (96,485 C/mol)Q is the reaction quotientIn this case, the cell reaction is:Zn(s) + 2H+(aq) → Zn2+(aq) + H2(g)and the reaction quotient is:Q = [Zn2+][H2]/[H+]2Substituting the given values into the Nernst equation, we get:0.66 V = 0.76 V - (0.0257 V/K)(298 K)/2(96,485 C/mol)ln([Zn2+][H2]/[H+]2)Solving for [H+], we get:[H+] = 4.2 × 10-4 M

The Standard Cell Potential (E°)of a Voltaic Cell Constructed Using