5.478 grams of potassium acetate and 2.143 grams of iron(III) hydroxide are added to a beaker containing 100.0 mL of water and stirred vigorously. A solid settles to the bottom of the beaker. If the water is decanted and the solid is dried, what is the maximum mass of solid that should be recovered

Respuesta :

Solution :

[tex]$Fe(OH)_3+3CH_3COOK \rightarrow Fe(CH_3COO)_3 + 3KOH$[/tex]

(iron          (potassium

hydroxide)     acetate)

Number of moles of [tex]$Fe(OH)_3 = \frac{\text{mass of }Fe(OH)_3}{\text{molar mass of }Fe(OH)_3}$[/tex]

                                                [tex]$=\frac{2.143 \ g}{106.867 \ g/mol}$[/tex]

                                                = 0.02005 mol

Number of moles of [tex]$CH_3COOK = \frac{\text{mass of }CH_3COOK}{\text{molar mass of }CH_3COOK}$[/tex]

                                                [tex]$=\frac{5.478 \ g}{98.15 \ g/mol}$[/tex]

                                                = 0.0585 mol

Since 1 mol of [tex]$Fe(OH)_3$[/tex] reacts with 3 mols of [tex]$CH_3COOK$[/tex]

Therefore, number of moles of [tex]$CH_3COOK$[/tex] reacted [tex]$=\frac{0.0585}{3 }$[/tex] mol

                                                                                    = 0.0195 mol

Therefore the limiting reagent is [tex]$CH_3COOK$[/tex] and hence the number of moles of [tex]$Fe(CH_3COO)_3$[/tex] produced is 0.0195 mol

Amount of [tex]$Fe(CH_3COO)_3$[/tex]  produced = moles x molar mass

                                                           = 0.0195 moles x 232.98 g/mol

                                                          = 4.5431 g