Reacting 959 mol of SiO2 with excess carbon yields 28.8 kg of SiC. What is the percentage yield?
SiO2 + 3C--> SiC + 2 CO
You must determine first the theoretical yield.
Using the coefficients in the balanced equation, convert moles SiO2 to moles SiC.
Convert moles SiC to grams. g = moles x molar mass. This is the theoretical yield.
%yield = [actual yield/theoretical yield]*100 = ??
actual yield is given in the problem as 28.8 kg but you must change this to grams OR change the theoretical yield to kg.
To calculate the percentage yield, we need to compare the actual yield (the amount of product obtained) with the theoretical yield (the amount of product expected based on stoichiometry).
In this reaction, we are given that 959 mol of SiO2 reacts with excess carbon to produce 28.8 kg of SiC.
1. First, let's calculate the molar mass of SiC.
The molar mass of SiC is the sum of the molar masses of silicon (Si) and carbon (C):
Si: 28.0855 g/mol
C: 12.011 g/mol
SiC: 28.0855 g/mol + 12.011 g/mol = 40.0965 g/mol
2. Next, calculate the theoretical yield of SiC in grams.
The molar ratio between SiO2 and SiC is 1:1 (from the balanced equation). Therefore, the moles of SiC produced will be equal to the moles of SiO2 used: 959 mol.
Now, we can use the molar mass of SiC to calculate the theoretical yield:
Theoretical yield = moles of SiC * molar mass of SiC
Theoretical yield = 959 mol * 40.0965 g/mol
3. Finally, convert the theoretical yield to kilograms:
Theoretical yield in kg = (959 mol * 40.0965 g/mol) / 1000 g/kg
Now that we have the theoretical yield in kilograms, we can calculate the percentage yield:
Percentage yield = (Actual yield / Theoretical yield) * 100
Given that the actual yield is 28.8 kg, and the theoretical yield is calculated as mentioned above, you can substitute these values into the formula:
Percentage yield = (28.8 kg / (959 mol * 40.0965 g/mol / 1000 g/kg)) * 100
Calculating this expression will give you the percentage yield.