The reaction mixture initially contains 2.5 grams of ferrous ammonium sulfate hexahydrate and 10.00 mL of 1.5 M oxalic acid. Determine the limiting reactant.
convert to moles
the reaction equation will then indicate the ratios used, and thus which will be exhausted.
Post your work if you get stuck. The molar mass of ferrous ammonium sulfate hexahydrate is 392.1.
To determine the limiting reactant in a chemical reaction, you need to compare the number of moles of each reactant and their stoichiometric coefficients.
First, let's calculate the number of moles for each reactant:
1. Ferrous ammonium sulfate hexahydrate (Fe(NH4)2(SO4)2·6H2O):
The molar mass of ferrous ammonium sulfate hexahydrate is:
(1 x atomic mass of Fe) + (2 x atomic mass of N) + (8 x atomic mass of H) + (2 x atomic mass of S) + (8 x atomic mass of O) + (24 x atomic mass of H2O)
= (1 x 55.85 g/mol) + (2 x 14.01 g/mol) + (8 x 1.01 g/mol) + (2 x 32.07 g/mol) + (8 x 16.00 g/mol) + (24 x 18.02 g/mol)
= 392.13 g/mol
Now, let's calculate the number of moles of ferrous ammonium sulfate hexahydrate:
Moles = Mass / Molar mass
= 2.5 g / 392.13 g/mol
≈ 0.0064 mol
2. Oxalic acid (H2C2O4):
The molar mass of oxalic acid is:
(2 x atomic mass of H) + (2 x atomic mass of C) + (4 x atomic mass of O)
= (2 x 1.01 g/mol) + (2 x 12.01 g/mol) + (4 x 16.00 g/mol)
= 90.03 g/mol
Now, let's calculate the number of moles of oxalic acid:
Moles = Volume x Concentration
Convert the volume from mL to L:
10.00 mL = 10.00 mL x (1 L / 1000 mL) = 0.010 L
Moles = 0.010 L x 1.5 mol/L
= 0.015 mol
Now that we have the number of moles for each reactant, we can compare them to find the limiting reactant. The reactant that produces fewer moles of product is the limiting reactant.
The balanced equation for the reaction between ferrous ammonium sulfate hexahydrate and oxalic acid is:
Fe(NH4)2(SO4)2·6H2O + H2C2O4 -> FeC2O4 + (NH4)2SO4 + 6H2O
From the balanced equation, we can see that the stoichiometric coefficient of ferrous ammonium sulfate hexahydrate is 1, and the stoichiometric coefficient of oxalic acid is also 1.
Comparing the number of moles, we can see that we have 0.0064 mol of ferrous ammonium sulfate hexahydrate and 0.015 mol of oxalic acid.
Since the number of moles of ferrous ammonium sulfate hexahydrate is smaller than the number of moles of oxalic acid, it is the limiting reactant.