Final answer:
The overall cell potential of the electrochemical cell is -1.95V.
Step-by-step explanation:
The overall cell potential of an electrochemical cell can be calculated by finding the difference between the reduction potentials of the cathode and the anode. In this case, the reduction potential of Mn2+ to Mn is -1.18V, and the reduction potential of Fe3+ to Fe2+ is 0.77V. To find the overall cell potential, we subtract the anode potential from the cathode potential: -1.18V - 0.77V = -1.95V.
Therefore, the correct answer is -1.95 V (option b).