Using the following standard reduction potentials Fe^3+(aq) + e^- rightarrow Fe^2+ (aq) E degree = + 0.77 V Pb^2+(aq) + 2e^- rightarrow Pb(s) E degree = -0.13 V calculate the standard cell potential for the galvanic cell reaction given below, and determine whether or not this reaction is spontaneous under standard conditions Pb^2+(aq) + 2 Fe^2+ (aq) rightarrow 2Fe^3+(aq) + Pb(s) E degree = +0.90 V, nonspontaneous E degree = -0.90 V, spontaneous E degree = -0.90 V, nonspontaneous E degree = +0.90 V, spontaneous