I am supposed to calculate the theoretical mass and moles of Cu. However I am given the mass of 2 reactants in the balanced equation:
3CuCl2*2H2O + 2Al -> 3Cu + 2AlCl3 + 6H2O
I am given the mass of CuCl2*2H2O to be 0.477g and the mass of Al is 0.267g. If I wanted to calculated the theoretical moles and mass of Cu produced which one do I use? The mass with the Cu or the mass of the Al? I tried using both of them by converting them to moles and then to the ratio of mole from the balanced equation but got two different results. One must be incorrect and one must be correct. Help please?
You do not have enough of one or the other, limiting the amount of Cu resulting.
Use the one you do not have enough of. Your mols of Al must be at least 2/3 the number of mols of CuCl....... If it is less use it. If it is more use the CuCl ... and you will have some Al left over
To calculate the theoretical mass and moles of Cu produced in the reaction, you need to determine the limiting reactant.
The limiting reactant is the reactant that is completely consumed or reacted in the reaction, thereby limiting the amount of product that can be formed. To identify the limiting reactant, compare the moles of each reactant to their respective stoichiometric coefficients in the balanced equation.
Let's calculate the moles of each reactant first.
For CuCl2*2H2O:
Given mass of CuCl2*2H2O = 0.477g
To convert mass to moles, use the formula:
moles = mass / molar mass
The molar mass of CuCl2*2H2O can be calculated by adding the molar masses of its constituents:
Cu: 63.55 g/mol
Cl: 35.45 g/mol (x 2 because there are 2 Cl atoms)
H: 1.008 g/mol (x 4 because there are 4 H atoms)
O: 16.00 g/mol (x 2 because there are 2 O atoms)
So, molar mass of CuCl2*2H2O = (63.55 + 2 x 35.45 + 4 x 1.008 + 2 x 16.00) g/mol = 170.48 g/mol
Now, calculate the moles of CuCl2*2H2O:
moles of CuCl2*2H2O = 0.477g / 170.48 g/mol
For Al:
Given mass of Al = 0.267g
To convert mass to moles, use the formula:
moles = mass / molar mass
The molar mass of Al is directly given as 26.98 g/mol.
Now, calculate the moles of Al:
moles of Al = 0.267g / 26.98 g/mol
Now that you have the moles of both reactants, compare them to the stoichiometric coefficients from the balanced equation:
3CuCl2*2H2O + 2Al -> 3Cu + 2AlCl3 + 6H2O
The ratio of moles between CuCl2*2H2O and Cu is 3:3, or 1:1, meaning that 1 mole of CuCl2*2H2O produces 1 mole of Cu.
The ratio of moles between Al and Cu is 2:3, meaning that 2 moles of Al produce 3 moles of Cu.
Compare the moles obtained from the two reactants and determine the limiting reactant. The reactant that produces fewer moles of Cu determines the maximum amount of Cu that can be produced. Use the moles of the limiting reactant to calculate the theoretical mass of Cu.
After determining the limiting reactant, you can calculate the theoretical moles and mass of Cu produced using the stoichiometric ratio from the balanced equation.
I hope this helps! Let me know if you have any further questions.