Respuesta :
Explanation:
According to the reaction, 2 moles of [tex]FeSO_{4}.7H_{2}O[/tex] = [tex]Fe_{2}O_{3}[/tex]
Molar mass of [tex]Fe_{2}O_{3}[/tex] is 159.69 g/mol and mass is given as 0.201 g.
Therefore, calculate the number of moles of [tex]Fe_{2}O_{3}[/tex] as follows.
No. of moles = [tex]\frac{mass}{\text{molar mass}}[/tex]
= [tex]\frac{0.201 g}{159.69 g/mol}[/tex]
= [tex]1.25 \times 10^{-3}[/tex] mol
Hence, moles of [tex]FeSO_{4}.7H_{2}O[/tex] = 2 × moles of [tex]Fe_{2}O_{3}[/tex]
Therefore, moles of [tex]FeSO_{4}.7H_{2}O[/tex] = [tex]2 \times 1.25 \times 10^{-3}[/tex] mol
= 0.0025 mol
Now, calculate the mass of [tex]FeSO_{4}.7H_{2}O[/tex] as follows.
No. of moles = [tex]\frac{mass}{\text{molar mass}}[/tex]
mass = no. of moles × molar mass of [tex]FeSO_{4}.7H_{2}O[/tex]
= [tex]0.0025 mol \times 278.01 g/mol[/tex]
= 0.695 g
Thus, we can conclude that 0.695 g is the mass of [tex]FeSO_{4}.7H_{2}O[/tex] in 2.955 g of the given sample.
