Now, let's finish the calculation and the determination of the formula of the iron compound: Calculate the % water of hydration : Tries 0/3 Calculate the following for Fe3 : g in 100 g sample mol in 100 g sample mol/mol Fe (3 sig figs) mol/mol Fe (whole number) Tries 0/3 Calculate the following for K : g in 100 g sample mol in 100 g sample mol/mol Fe (3 sig figs) mol/mol Fe (whole number) Tries 0/3 Calculate the following for C2O42-: g in 100 g sample mol in 100 g sample mol/mol Fe (3 sig figs) mol/mol Fe (whole number) Tries 0/3 Calculate the following for H2O g in 100 g sample mol in 100 g sample mol/mol Fe (3 sig figs) mol/mol Fe (whole number)

Respuesta :

Complete Question

The complete question is shown on the first and second uploaded image

Answer:

A

The percentage of water of hydration is   [tex]P_h= 11.01[/tex]%

Mass of [tex]Fe^{3+}[/tex] in 100mg is 10.60mg

Moles of  [tex]Fe^{3+}[/tex] in 100mg is [tex]n_i= 0.19[/tex]

mol / mol Fe (3 sig figs) is [tex]= 1.00[/tex]

mol / mol Fe (whole number) is = 1

B

Mass of [tex]K^{+}[/tex] in 100mg is 27.70mg

Moles of  [tex]K^{+}[/tex] in 100mg is [tex]n_i= 0.581 moles[/tex]

mol  of K / mol of Fe (3 sig figs) is [tex]= 3.05[/tex]

mol  of K / mol of Fe (whole number) is [tex]=3[/tex]

C

Mass of [tex]C_2O_4^{-2}[/tex] in 100mg is 55.69 mg

Moles of [tex]C_2O_4^{-2}[/tex]  in 100mg is [tex]n_i= 0.633 moles[/tex]

mol  of  [tex]C_2O_4^{-2}[/tex] / mol of Fe (3 sig figs) is [tex]= 3.33[/tex]

mol  of [tex]C_2O_4^{-2}[/tex] / mol of Fe (whole number) is [tex]=3[/tex]

D

Mass of water in 100mg is 11.01 mg

Moles of water  in 100mg is [tex]n_i= 0.611 moles[/tex]

mol  of  water / mol of Fe (3 sig figs) is [tex]= 3.21[/tex]

mol  of water / mol of Fe (whole number) is [tex]=3[/tex]

Explanation:

The percentage of water of hydration is mathematically represented as

        [tex]P_h = 100 - (Pi + P_p + P_o)[/tex]

Now substituting 10.60% for [tex]P_i[/tex] (percentage of iron ) , 22.70% for [tex]P_p[/tex](Percentage of potassium) , 55.69% for [tex]P_o[/tex] (percentage of Oxlate)

        [tex]P_h =100 - (10.60 + 22.70+55.69)[/tex]

             [tex]P_h= 11.01[/tex]%

For IRON

Since the percentage of [tex]Fe^{3+}[/tex] is 10.60% then in a 100 mg of the sample the amount of [tex]Fe^{3+}[/tex] would be 10.60 mg

  Now the no of moles is mathematically denoted as

            [tex]n = \frac{mass}{molar \ mass }[/tex]

The molar mass of [tex]Fe[/tex] is  55.485 g/mol

     So the number of moles of [tex]Fe^{3+}[/tex] in 100mg of he sample is

                  [tex]n_i = \frac{10.60}{55.485}[/tex]

                       [tex]n_i= 0.19[/tex]

mol / mol Fe (3 sig figs) is [tex]= \frac{0.19}{0.19} = 1.00[/tex]

FOR POTASSIUM

Since the percentage of [tex]K^{+}[/tex] is 22.70% then in a 100mg of the sample the amount of [tex]K^{+}[/tex] would be 22.70mg

The molar mass of [tex]K[/tex] is  39.1 g/mol

   So the number of moles of [tex]K^{+}[/tex] in 100mg of he sample is

                  [tex]n_i = \frac{22.70}{39.1}[/tex]

                      [tex]=0.581 moles[/tex]

mol  of K / mol of Fe (3 sig figs) is [tex]= \frac{0.581}{0.19} = 3.05[/tex]

FOR OXILATE [tex]C_2O_4^{-2}[/tex]

Since the percentage of [tex]C_2O_4^{-2}[/tex]  is 55.69% then in a 100mg of the sample the amount of [tex]C_2O_4^{-2}[/tex] would be 55.69 mg

The molar mass of [tex]C_2O_4^{-2}[/tex] is  88.02 g/mol

  So the number of moles of [tex]C_2O_4^{-2}[/tex]   in 100mg of he sample is

                  [tex]n_i = \frac{55.69}{88.02}[/tex]

                         [tex]=0.633 moles[/tex]

mol  of [tex]C_2O_4^{-2}[/tex] / mol of Fe (3 sig figs) is  [tex]= \frac{0.633}{0.19} = 3.33[/tex]

FOR WATER OF HYDRATION

        Since the percentage of water  is 11.01% then in a 100mg of the sample the amount of water would be 11.0 mg

   The molar mass of water  is  18.0 g/mol

  So the number of moles of water   in 100mg of he sample is

                  [tex]n_i = \frac{11.01}{18.0}[/tex]

                      [tex]=0.611 moles[/tex]

mol  of  water / mol of Fe (3 sig figs) is  [tex]= \frac{0.611}{0.19} = 3.21[/tex]

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