Question

Calculate the molecular mass of CaSO₄.

Answer 1

1. Molar mass is the sum of the masses of all the individual atoms present in a molecule or compound.
2. Chemical formula of Calcium sulphate is CaSO₄.
3. Atomic mass of Calcium Ca is 40 u.
4. Atomic mass of Sulphur S is 32 u.
5. Atomic mass of Oxygen is 16 u.

Molecular mass of Calcium sulphate is CaSO₄ = ( Atomic mass of Calcium ) x 1 + (Atomic mass of Sulphur) x 1 + (Atomic mass of Oxygen) x 4

= ( 40 x 1 ) + ( 32 x 1 ) + ( 16 x 4 )

= 40 + 32 + 64

= 136 u.

Molecular mass of Calcium sulphate is CaSO₄ is 136 u.