Question

A bivalent metal has an equivalent mass of 20.the molecular mass of the metal sulphate is

Answer 1

equivalent mass of bivalent metal is 20.

for bivalent metal , valency = 2

we know, equivalent mass of metal = atomic mass of metal/valency

so, 20 = atomic mass of metal/2

or, atomic mass of metal = 2 × 20 = 40g/mol.

Let M is bivalent molecular then, chemical formula of metal sulphate is $MSO_4$.

now, molecular mass of metal sulphate = atomic mass of metal + atomic mass of sulphur + 4 × atomic mass of Oxygen

= 40g/mol + 32g/mol + 64g/mol

= 136 g/mol.

hence, molecular mass of metal sulphate is 136 g/mol