given the measured cell potential, Ecell is -.3569V at 25 degree c, calculate the H+ concentration

Pt(s)|H2(g) (.755atm)|H+(?)||Cd^2+(1.00M|Cd(s)

Ecell standard = .403
n=2e-

Question

given the measured cell potential, Ecell is -.3569V at 25 degree c, calculate the H+ concentration 

Pt(s)|H2(g) (.755atm)|H+(?)||Cd^2+(1.00M|Cd(s)

Ecell standard = .403
n=2e-

jfraser · Answer

You need to use the Nernst equation:
$$E_{cell} = E^0_{cell} - \frac{RT}{nF}*ln(Q)$$ to solve for the reaction quotient, Q, then plug in the concentrations and pressures to find the $[H^+]$.