Answer:
16.93%.
Explanation:
∴ The mass of 1.0 mol of Fe₃Al₂(SiO₄)₃ = (no. of moles of Fe₃Al₂(SiO₄)₃)(the molecular mass of Fe₃Al₂(SiO₄)₃)
∴ The mass of 1.0 mol of Fe₃Al₂(SiO₄)₃ = (1)(the molecular mass of Fe₃Al₂(SiO₄)₃) = (the molecular mass of Fe₃Al₂(SiO₄)₃).
∴ The mass of 1.0 mol of Fe₃Al₂(SiO₄)₃ = 3(atomic weight of Fe) + 2(atomic weight of Al) + 3(molecular weight of (SiO₄)₃) = 497.7474 g.
The mass of Si in 1.0 mole of Fe₃Al₂(SiO₄)₃ = 3(atomic mass of Si) = 3(28.0855 g/mol) = 84.2565 g.
∵ The mass % of Si = (the mass of Si)/(the mass of Fe₃Al₂(SiO₄)₃) = (84.2565 g)/(497.7474 g) = 16.93%.
