The correct option is A 3.9×1025
From the formula unit of (MgSO4.7H2O), 11 moles of O atoms are present in 1 mole of MgSO4.7H2O.
Therefore, 5.5 moles of O atoms will be present in
=5.511 moles of MgSO4.7H2O
Again, the total number of electrons in one formula unit of MgSO4.7H2O
=1×12+1×16+14+11×8=130
So, the total number of electrons in one mole of MgSO4.7H2O
=130×6×1023
Therefore, the total number of electrons in 5.511 moles of MgSO4.7H2O
=130×6×1023×12=3.9×1025