Calculate the mass per cent of different elements present in sodium sulphate (Na2SO4).

Atomic Mass of Sodium = 23g

Atomic Mass of Sulphur = 32g


Atomic Mass of Oxygen = 16g


From the molecular formula of sodium sulphate, it is understood that in 1 mole of sodium sulphate, 1 mole of sulphur, 4 moles of oxygen and 2 moles of sodium is present.


So Molecular Mass of Sodium Sulphate = [23×2] + [32×1] + [16×4]


= 46 + 32 + 64


= 142g


Percentage of Sodium in sodium sulphate = [46×100]/142


= [4600/142]


= 32.394%


Percentage of Sulphur in sodium sulphate = [32×100]/142


= 3200/142


= 22.535%


Percentage of Oxygen in sodium sulphate = [64×100]/142


= 6400/142


=45.070%


Therefore, the percentage of different elements in sodium sulphate is given below:



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