Question

Calculate the value of Eocell for the following reaction: 2Co3+(aq) + 3Ca(s) --> 2Co(s) + 3Ca2+(aq) Co3+(aq) + 3e– --> Co(s) Eo = 1.54 V Ca2+(aq) + 2e– --> Ca(s) Eo = –2.87 V.

A. –1.33 V

B. +1.33 V

C. –4.41 V

D. –11.6 V

E. +4.41 V

Answer 1

Since the reduction potential of Co³⁺ is more it is the cathodic reaction,so the

Standard potential of the cell , E^o = E^o_cathode - E^o_anode

                                                  = E^o_Co3+/Co - E^o_Ca2+/Ca

                                                  = +1.54 - (-2.87) V

                                                  = +1.33 V

Therefore the correct option is (B)