What is the percentage yield if 110.6 g of malachite are formed when 1.5 moles of copper sulfate reacts with an excess of sodium carbonate?
CuSO4 + Na2CO3 ==> CuCO3 + Na2SO4
1.5 mols CuSO4 will produce 1.5 moles of CuCO3 theoretically and 1.5 mols = 1.5 x 123.5 = 185 g CuCO3. This is the expected yield at 100%.
% yield = (actual yield/expected yield)*100 = (110.6/185)*100 = ?
determine how many moles you expected.
divide yield by expectation
But how would you find the expectation?
To calculate the percentage yield, you need to know the actual yield (in grams) and the theoretical yield (also in grams) of the reaction.
The theoretical yield is the maximum amount of product that can be obtained based on stoichiometry. In this case, you need to calculate the theoretical yield of malachite.
First, you need to write the balanced equation for the reaction between copper sulfate (CuSO4) and sodium carbonate (Na2CO3). It is:
CuSO4 + Na2CO3 -> CuCO3 + Na2SO4
From the balanced equation, you can determine the stoichiometric ratio between copper sulfate and malachite. Since one mole of copper sulfate reacts to form one mole of malachite, the moles of malachite should be the same as the moles of copper sulfate.
Given that 1.5 moles of copper sulfate reacted, the number of moles of malachite formed is also 1.5 moles.
To calculate the theoretical yield of malachite (in grams), you need to multiply the number of moles (1.5 moles) by the molar mass of malachite (which is the sum of the atomic masses of the elements in malachite). The molar mass of malachite can be determined by adding the atomic masses of copper (Cu), carbon (C), and three oxygen (O) atoms.
Once you have calculated the theoretical yield in grams, you can now compare it with the actual yield given in the problem (110.6 g).
The percentage yield is then calculated using the following formula:
Percentage Yield = (Actual Yield / Theoretical Yield) x 100
Inserting the values into the formula:
Percentage Yield = (110.6 g / Theoretical Yield) x 100
So, to find the percentage yield, you need to calculate the theoretical yield in grams and then apply the formula mentioned above.