Question

40.4 g of Fe(NO3)3.9H2O is dissolved in sufficient water to make up one litre of solution. Find

the concentrations of iron(III) ions and nitrate ions

Answer 1

0.3 moles /liter

Step-by-step explanation:

The molar mass of Fe(NO3)3.9H2O is 403.99

40.4 g of Fe(NO3)3.9H2O is approximately equivalent to 40.4/404.4 = 0.1 moles

As each unit of the hydrated iron nitrate contributes one unit of iron(3) ions, the concentration of iron(3) ions in the solution is 0.1 moles/liter.

As each unit of the hydrated iron nitrate contributes 3 units of nitrate ions, the concentration of nitrate ions if 0.3 moles/liter.