Q.
A metal M forms the sulphate M2(SO4)3. A 0.596 gram sample of the sulphate reacts with excess BaCl2 to give 1.220gBaSO4. What is the atomic weight of M (in g/mol )? (Molarmassof(BaSO)4=233.3g/mol)
The balanced equation for the given reaction is, M2(SO4)3+3BaCl2→2MCl3+3BaSO4
Mole of BaSO4=233.31.22mol
By stoichiometry of reaction:
Moles of M2(SO4)3=233.31.22×31 =1.743×10−3mol
Mass of M2(SO4)3=0.596g ∴1.743×10−3(2M+96×3)=0.596M=26.9g/mol