how do i calculate the number of moles of ammonium iron (ll) sulphate (NH4)2 Fe(SO4)2.6H2O in 1dm3 of solution?
A cubic decimeter is one liter. What is the concentration (Molarity) of the solution? You need to know that to answer the question.
The mass of one mole of the hydrated compound is easily calculated. Have you tried that?
Yea
Calculate the number of moles of iron 2 ammonium sulphate solution
To calculate the number of moles of ammonium iron (II) sulfate [(NH4)2Fe(SO4)2.6H2O] in 1 dm3 of solution, we need to use the equation:
number of moles = mass / molar mass
Step 1: Find the molar mass of [(NH4)2Fe(SO4)2.6H2O]
The molar mass is the sum of the atomic masses of all the atoms in the compound. Use the periodic table to find the atomic masses of each element and multiply them by the respective subscripts.
(NH4)2Fe(SO4)2.6H2O:
- Two ammonium ions (NH4): 2 x (14.01 g/mol) = 28.02 g/mol
- One iron (II) ion (Fe): 1 x (55.85 g/mol) = 55.85 g/mol
- Two sulfate ions (SO4): 2 x [(32.07 g/mol) + (4 x 16.00 g/mol)] = 2 x 96.12 g/mol = 192.24 g/mol
- Six water molecules (H2O): 6 x [(2 x 1.01 g/mol) + (16.00 g/mol)] = 6 x 18.02 g/mol = 108.12 g/mol
Now, add up the individual molar masses:
28.02 g/mol + 55.85 g/mol + 192.24 g/mol + 108.12 g/mol = 384.23 g/mol
So, the molar mass of [(NH4)2Fe(SO4)2.6H2O] is 384.23 g/mol.
Step 2: Calculate the number of moles
To calculate the number of moles, divide the mass of the compound by its molar mass. Since we are given 1 dm3 of solution, the mass will be in grams:
number of moles = mass / molar mass
Make sure the units cancel out properly to get moles. In this case, we need to use the density of the compound to convert the volume (dm3) to mass (grams).
Once you have the mass, substitute it into the equation along with the molar mass:
number of moles = (mass of compound) / molar mass
This calculation will give you the number of moles of ammonium iron (II) sulfate in 1 dm3 of solution.