The standard reduction potentials for two half-cells are given below: E^ ( Ni ²⁺/ Ni ) = -0.25 V E^ ( Ag ⁺/ Ag ) = +0.80 V Calculate the standard Gibbs energy change ( _ r G^ ) for the spontaneous cell reaction formed by these two electrodes. (Given : 1 F = 96500 C mol ⁻¹ )

Step-by-step solution

For a spontaneous reaction, the standard cell potential ( E_ cell ^ ) must be positive. The electrode with the higher standard reduction potential acts as the cathode (Ag), and the one with the lower standard reduction potential acts as the anode (Ni). E_ cell ^ = E_ cathode ^ - E_ anode ^ E_ cell ^ = 0.80 V - (-0.25 V ) = 1.05 V The balanced spontaneous cell reaction is: Ni(s) + 2 Ag ⁺ (aq) Ni ²⁺ (aq) + 2 Ag(s) The number of moles of electrons transferred ( n ) is 2 . The standard Gibbs energy change is: _ r G^ =