Respuesta :

Molar mass of iron(III)sulfate that is Fe₂(SO₄)₃ =399.88 g mol⁻¹  

Mass given of  iron(III)sulfate that is Fe₂(SO₄)₃= 0.275 g

Number of moles of iron(III)sulfate that is Fe₂(SO₄)₃= [tex]\frac{0.275}{399.88}[/tex]  

                                                                                  =0.00068 mol

there are two moles of Fe in 1 mole of Fe₂(SO₄)₃

So, in 0.00068 mol of Fe₂(SO₄)₃=2 ×0.00068 mol of Fe

                                                  = 0.00136 mol of Fe

molar mass of Fe=55.8 g mol⁻¹

So the mass of iron in 0.00136 mol of Fe= 55.8 g mol⁻¹ × 0.00136 mol

                                                                  =0.075 g

Mass of iron  = [tex]0.275 grams[/tex]

The chemical formula of iron (III) sulfate = [tex]Fe_{2}(SO_{4})_{3}[/tex]

First, calculate the number of moles of [tex]Fe_{2}(SO_{4})_{3}[/tex]

Number of moles of iron (III) sulfate = [tex]\frac{given mass in g}{molar mass}[/tex]

Molar mass of iron (III) sulfate = 399.88 g/mol

Number of moles of iron (III) sulfate  = [tex]\frac{0.275 g}{399.88 g/mol}[/tex]

= [tex]6.87\times 10^{-4} mol[/tex]

In one mole of iron (III) sulfate there are two moles of iron according to the chemical formula.

So, in [tex]6.87\times 10^{-4} mol[/tex] of iron (III) sulfate there are =[tex] 2\times 6.87 \times 10^{-4} mol[/tex] of iron.

Number of moles of iron  =[tex]13.74\times 10^{-4} mol[/tex]

Molar mass of iron  = [tex]55.8 g/mol[/tex]

Mass of iron  =[tex]number of moles \times molar mass[/tex]

= [tex]13.74\times 10^{-4} mol \times 55.8 g/mol[/tex]

= [tex]766.692 \times 10^{-4}  g[/tex]

= [tex]7.66 \times 10^{-2}  g[/tex]

Hence, mass of iron = [tex]7.66 \times 10^{-2}  g[/tex]