A piece of an aluminum can was cut into small pieces. Then 0.422 g of the chips from the can was used to
prepare potassium alum according to the procedure we used. Calculate the theoretical yield (in g) of potassium
alum that could be obtained in the reaction. (Alum MW=474.41 g/mol).
It would help if we had the reaction you used.
To calculate the theoretical yield of potassium alum, we need to know the molar mass of aluminum (Al) and the balanced chemical equation for the reaction that converts aluminum chips into potassium alum.
The molar mass of aluminum (Al) is 26.98 g/mol.
Now, let's write the balanced chemical equation for the reaction:
2 Al + K2SO4 + 4 H2O → 2 KAl(SO4)2 . 12 H2O
From the balanced equation, we can see that 2 moles of aluminum (Al) react to form 1 mole of potassium alum (KAl(SO4)2 . 12H2O).
To calculate the theoretical yield, we will follow these steps:
1. Convert the mass of aluminum chips used (0.422 g) to moles using the molar mass of aluminum.
moles of Al = mass of Al / molar mass of Al
moles of Al = 0.422 g / 26.98 g/mol
2. Calculate the moles of potassium alum that can be formed by multiplying the moles of aluminum by the mole ratio from the balanced equation.
moles of KAl(SO4)2 . 12 H2O = moles of Al x (1 mole of KAl(SO4)2 . 12 H2O / 2 moles of Al)
3. Convert the moles of potassium alum to grams using the molar mass of potassium alum.
mass of KAl(SO4)2 . 12 H2O = moles of KAl(SO4)2 . 12 H2O x molar mass of KAl(SO4)2 . 12 H2O
Let's do the calculations:
1. moles of Al = 0.422 g / 26.98 g/mol
moles of Al = 0.015651 moles
2. moles of KAl(SO4)2 . 12 H2O = 0.015651 moles x (1 mole / 2 moles of Al)
moles of KAl(SO4)2 . 12 H2O = 0.015651 moles / 2
moles of KAl(SO4)2 . 12 H2O = 0.007826 moles
3. mass of KAl(SO4)2 . 12 H2O = 0.007826 moles x 474.41 g/mol
mass of KAl(SO4)2 . 12 H2O = 3.7116 g
Therefore, the theoretical yield of potassium alum that could be obtained in the reaction is 3.7116 g.