If the total number of electrons present in a pure sample of FeSO4.7H2O is 4.336×1026
then the total number of moles of oxygen atoms present in FeSO4.7H2O:
The total number of electrons in one formula unit of FeSO4.7H2O
=(26+16+4×8+14×1+7×8)=144
So, 144×6.022×1023 electrons are present in 1 mole of FeSO4.7H2O.
Hence, 4.336×1026 electrons will be present in
=4.336×10261.44×6.022×1023 moles of FeSO4.7H2O
=5 moles of FeSO4.7H2O
From the formula unit :
1 mole of FeSO4.7H2O contains 11 moles of O atoms.
Thus, 5 moles of FeSO4.7H2O will contains 55 moles of O atoms.