At the anode, a metal electrode (M) is placed in a saturated aqueous solution containing ions of the same metal (M) and a halogen (X), MX. At the cathode, a second electrode of the same metal (M) is placed in a solution with [M+] = 0.100 M.The two half-cells are connected by a salt bridge, and the measured cell voltage is 0.417 V. The cell reaction occurring in this concentration cell is