Answer:
2.53x10⁻³g of Ca(ClO₄)₂
Explanation:
It is possible to convert formula units to moles using Avogadro's number and then, these moles to grams with molar mass, thus:
6.37x10¹⁸F.U. ₓ (1mole / 6.022x10²³F.U.) = 1.06x10⁻⁵ moles of Ca(ClO₄)₂
Molar mass of Ca(ClO₄)₂ is:
1 Ca = 1×40.08g/mol = 40.08g/mol
2 Cl = 2×35.45g/mol = 70.90g/mol
8 O = 8×16g/mol = 128g/mol
Molar mass:
40.08g/mol + 70.90g/mol + 128g/mol = 238.98g/mol
Thus, mass of 1.06x10⁻⁵ moles of Ca(ClO₄)₂ is:
1.06x10⁻⁵ moles of Ca(ClO₄)₂ × (238.98g/mol) = 2.53x10⁻³g of Ca(ClO₄)₂
