In a balanced redox reaction net gain of electron (s) is equal to net loss of electrons (s).`n_("factor")` is a reaction specific parameter and for intermolecular redox reaction n-factor of oxidising reducing agent is the no. of moles of electron gained /lost by one mole of compound.
The `n_("factor")` of KI in the following reaction is :
`CuSO_(4)+KI to Cu_(2)I_(2)+K_(2)SO_(4)+I_(2)`