Balance the reaction
EoCell= EoRed,Cathode - EoRed,Anode
Ecell = 0.9 - 0.15 = +0.75
v is the electrons exchanged = 2e- but notice in the equation it is is written -v so take care of that
F is Faraday constant
Answer will come in joules not in kilojoules but convert it to kilojoules because in exams examiner only accepts kilojoules as answer .