Consider the following reaction: 6FeSO4+K2Cr2O7+7H2SO4→3Fe2(SO4)3+Cr2(SO4)3+K2SO4+7H2O. How many electrons are involved in the redox reaction?
Two half reactions for the following equation are: 4H2SO4+K2Cr2O7+3Na2SO3⟶Cr2(SO4)3+K2SO4+3Na2SO4+4H2O