I was doing a lab experiment:
1) I measured 2.02g of copper(II) sulphate pentahydrate
2) I dissolved the copper(II) sulphate pentahydrate in 10mL of distilled water
3) I added 2.0mL of concentrated HCl to the solution and mixed well
4) I added 0.25g on Aluminun foil to the solution.
5) After 5 minutes, i added an additional 5mL of concentrated HCl
6) After all the aluminum foil has reacted, i decanted the solution from the solid (leaving copper behind).
7) The mass of copper product after drying it was 0.69g.
Now we have:
-Mass of CuSO4*5H2O = 2.02g
-Mass of Aluminuim foil = 0.25g
-Mass of copper metal product = 0.69g
The questions are:
1) Calculate moles of Al used.
2) Calculate the moles of CuSO4*5H2O used.
3) Calculate the moles of copper product based on moles of Al.
4) Calculate the moles of copper product based on moles of CuSO4*5H2O.
5) Whats the limiting reactant.
6) Whats the grams of copper product based on the limiting reactant (theoretical yiel).
7) Calculate the percent yield of Copper.
To answer these questions, we need to calculate the number of moles for each component involved in the reaction. We will use the given masses and molar masses of the substances.
1) Calculate moles of Al used:
- Mass of Aluminum foil = 0.25g
- Molar mass of Aluminum (Al) = 26.98 g/mol
Moles of Al = Mass of Al / Molar mass of Al
2) Calculate the moles of CuSO4*5H2O used:
- Mass of CuSO4*5H2O = 2.02g
- Molar mass of CuSO4*5H2O = (63.55 + 32.07 + 16.00*4 + 18.02*5) g/mol
Moles of CuSO4*5H2O = Mass of CuSO4*5H2O / Molar mass of CuSO4*5H2O
3) Calculate the moles of copper product based on moles of Al:
The balanced chemical equation for the reaction between aluminum and copper(II) sulfate is:
2Al + 3CuSO4 → Al2(SO4)3 + 3Cu
From the equation, we see that the mole ratio between aluminum (Al) and copper (Cu) is 2:3.
Moles of Cu = (Moles of Al used) * (3 moles of Cu / 2 moles of Al)
4) Calculate the moles of copper product based on moles of CuSO4*5H2O:
From the balanced chemical equation, the mole ratio between copper(II) sulfate (CuSO4) and copper (Cu) is 3:3 (or 1:1).
Moles of Cu = Moles of CuSO4*5H2O
5) Determine the limiting reactant:
The reactant that produces the lesser amount of product is the limiting reactant.
To determine the limiting reactant, compare the moles of copper obtained based on moles of Al (from step 3) and moles of CuSO4*5H2O (from step 4). The reactant with a lower moles of Cu is the limiting reactant.
6) Calculate the grams of copper product based on the limiting reactant (theoretical yield):
To determine the theoretical yield, you need to convert the moles of the limiting reactant (Cu or CuSO4*5H2O) to grams of copper (Cu).
- Molar mass of Cu = 63.55 g/mol
Grams of Cu = Moles of Cu (from step 3 or 4) * Molar mass of Cu
7) Calculate the percent yield of Copper:
Percent yield = (Actual yield / Theoretical yield) * 100
Use the given mass of copper product (0.69g) as the actual yield and the grams of copper product (theoretical yield from step 6) as the theoretical yield.