Answer:
0.078×10²³ molecules
Step-by-step explanation:
Given data:
Mass of iron(II) hydroxide = 3.6 g
Molecules of iron(II) phosphate = ?
Solution:
Chemical equation:
3Fe(OH)₂ + Ca₃(PO₄)₂ → Fe₃(PO₄)₂ + 3Ca(OH)₂
Number of moles of Fe(OH)₂:
Number of moles = mass/ molar mass
Number of moles = 3.6 g/ 89.86 g/mol
Number of moles = 0.04 mol
Now we will compare the moles of iron(II) hydroxide with Fe₃(PO₄)₂:
Fe(OH)₂ : Fe₃(PO₄)₂
3 : 1
0.04 : 1/3×0.04 = 0.013
Number of molecules of Fe₃(PO₄)₂:
1 mole = 6.022×10²³ molecules
0.013 mole ×6.022×10²³ molecules/ 1 mol
0.078×10²³ molecules