An electrochemical cell is constructed with an open switch as shown below. When the switch is closed, mass of tin-electrode increase. If `E^(@)(Sn^(2+)//Sn)=-0.14V` and for `E^(@)(X^(n+)//X)=-0.78V` and initial emf of the cell is 0.65 V, determine n and indicate ad direction of electron flow in the external circuit.

Answer

`n=3`, since mass of `Sn` increasing `Sn`- electrode is working as cathode and X-metal electrode anode and electrons are flowing from X-electrode to Sn-electrode in the external circuit.