4 Fe + 3 O2 -> 2 Fe2O3
1. If I react 3.00g Fe and 5.75g O2, what is the theoretical yield?
2. If I’m only able to produce 3.5g, what is my percent yield?
3. If I try again, and get a 95.0% yield, what is my actual yield?
For the theo yield I got 0.026857655 mol of Fe, I need help on where to continue
4 Fe + 3 O2 -> 2 Fe2O3
I don't agree with your answers for theoretical yield
Part 2. (actual yield/theor yield)*100 = ?
Part 3. Same equation as for #2 but plug in 95% for yield and calculate yield.
Post your work if you get stuck.
actual yield
%Yield = [Actual Lab Yield mass/Theoretical Calculated Yield mass]100%
Theoretical Yield calculations are based upon the limited reactant in the problem; that is, in the posted problem the limiting reactant is the iron (Fe) with Oxygen remaining in excess giving 0.027 mole Fe2O3 (Theoretical). For the grams multiply by the formula weight of Fe2O3 (160 g/mole) => 4.32 gram theoretical yield.
%Yield = (Lab Yield/Theoretical Yield)100% =(3.5-g/4.32-g)100% = 81%
For 95% yield (Trial 2) => mass yield = 95% of Theoretical Yield = 0.95(4.32) grams = 4.10-grams (Trial 2).
To determine the theoretical yield, you have correctly calculated the number of moles of Fe. Now, you need to find the limiting reactant to determine how much Fe2O3 can be produced.
Let's calculate the number of moles of O2 using the molar mass of O2, which is 32 g/mol:
Moles of O2 = mass of O2 / molar mass of O2
Moles of O2 = 5.75 g / 32 g/mol
Moles of O2 = 0.1796875 mol
Now, we can compare the moles of Fe and O2 to determine the limiting reactant. According to the balanced equation, the ratio of Fe to O2 is 4:3. This means that for every 4 moles of Fe, you need 3 moles of O2.
Divide the number of moles of Fe and O2 by their respective coefficients in the balanced equation:
Moles of Fe / coefficient of Fe = 0.026857655 mol / 4 = 0.006714414 mol
Moles of O2 / coefficient of O2 = 0.1796875 mol / 3 = 0.059895833 mol
From these calculations, we can see that Fe is the limiting reactant because it produces less moles of product compared to the moles of O2.
Now, to find the theoretical yield of Fe2O3, we need to calculate the number of moles of Fe2O3 produced from the limiting reactant, Fe. According to the balanced equation, the ratio of Fe to Fe2O3 is 4:2, so for every 4 moles of Fe, you get 2 moles of Fe2O3.
Moles of Fe2O3 = Moles of Fe / (coefficient of Fe/ coefficient of Fe2O3)
Moles of Fe2O3 = 0.006714414 mol / (4/2)
Moles of Fe2O3 = 0.006714414 mol / 2
Moles of Fe2O3 = 0.003357207 mol
Therefore, the theoretical yield of Fe2O3 is 0.003357207 mol.
Let's proceed to the next question.
To find the theoretical yield, you initially calculated the number of moles of Fe. Now, you need to find the number of moles of Fe2O3 produced using the stoichiometry of the balanced equation.
First, calculate the number of moles of oxygen (O2) using its molar mass.
Given:
Mass of Fe = 3.00 g
Mass of O2 = 5.75 g
1. Calculate the number of moles of Fe:
Molar mass of Fe = 55.85 g/mol
Moles of Fe = Mass of Fe / Molar mass of Fe
Moles of Fe = 3.00 g / 55.85 g/mol = 0.0537 mol Fe
2. Calculate the number of moles of O2:
Molar mass of O2 = 32.00 g/mol
Moles of O2 = Mass of O2 / Molar mass of O2
Moles of O2 = 5.75 g / 32.00 g/mol = 0.1797 mol O2
3. Use the stoichiometry of the balanced equation to find the moles of Fe2O3 produced:
According to the balanced equation: 4 Fe + 3 O2 -> 2 Fe2O3
From the equation, we can see that for every 4 moles of Fe, 2 moles of Fe2O3 are produced. So, we can set up a proportion:
(0.0537 mol Fe / 4 mol Fe) = (x / 2 mol Fe2O3), where x represents the moles of Fe2O3.
Solve for x:
x = (0.0537 mol Fe / 4 mol Fe) * 2 mol Fe2O3
x = 0.0269 mol Fe2O3
Therefore, the theoretical yield of Fe2O3 is 0.0269 mol.
For the remaining questions, follow these steps:
2. Calculate percent yield:
Percent yield = (Actual yield / Theoretical yield) * 100
Given:
Actual yield = 3.5 g (in grams)
Convert the actual yield to moles:
Molar mass of Fe2O3 = 159.69 g/mol
Moles of Fe2O3 = Mass of Fe2O3 / Molar mass of Fe2O3
Moles of Fe2O3 = 3.5 g / 159.69 g/mol = 0.0219 mol Fe2O3
Calculate percent yield:
Percent yield = (0.0219 mol Fe2O3 / 0.0269 mol Fe2O3) * 100
3. Calculate actual yield:
Given:
Percent yield = 95.0% = 0.95 (in decimal form)
Actual yield = Percent yield * Theoretical yield
Actual yield = 0.95 * 0.0269 mol Fe2O3
Now you can calculate the actual yield in moles and convert it to grams if necessary.