The theoretical yield of Cl2 that could be prepared by mixing 15.0 g of manganese dioxide (MnO2) with 30.0 g of HCl is 12.2 g. The limiting reagent was MnO2. When the reaction was run only 8.82 g of Cl2 was collected. The percent yield of Cl2 is_?
a)58.8 %
b)72.3 %
c)29.4 %
d)81.3 %
e)unknown as there is not enough data to determine the percent yield
I calculated the answer is 58.8%, but i'm not sure. Can anyone please help me make sure this answer please.
No, if the problem states it correctly, the theoretical yield is 12.2g. You collected only 8.82 g so
%yield = (8.82/12.2)*100 =
Thank you so much DrBob222. Now I understand.
To determine the percent yield of Cl2, we need to compare the actual yield (8.82 g) to the theoretical yield (12.2 g) and calculate the percentage.
First, let's find the limiting reagent, which is the reactant that limits the amount of product that can be formed. To do this, we need to convert the given masses of MnO2 and HCl into moles.
The molar mass of MnO2 is 86.94 g/mol, and the molar mass of HCl is 36.46 g/mol.
To find the number of moles of MnO2:
moles of MnO2 = mass of MnO2 (g) / molar mass of MnO2
moles of MnO2 = 15.0 g / 86.94 g/mol
moles of MnO2 ≈ 0.17 mol
To find the number of moles of HCl:
moles of HCl = mass of HCl (g) / molar mass of HCl
moles of HCl = 30.0 g / 36.46 g/mol
moles of HCl ≈ 0.82 mol
Next, we need to determine the stoichiometry of the reaction to find the ratio of moles of reactants to moles of product. From the balanced chemical equation:
2 MnO2 + 4 HCl → 2 MnCl2 + 2 H2O + Cl2
We can see that for every 2 moles of MnO2, we produce 1 mole of Cl2. Therefore, the theoretical yield of Cl2 from 0.17 mol of MnO2 would be:
theoretical yield of Cl2 = (0.17 mol MnO2) / (2 mol MnO2/1 mol Cl2) * (1 mol Cl2) * (molar mass of Cl2)
theoretical yield of Cl2 ≈ 0.17 mol * (1 mol Cl2/2 mol MnO2) * 71.0 g/mol
theoretical yield of Cl2 ≈ 6.87 g
Now, we can calculate the percent yield:
percent yield = (actual yield / theoretical yield) * 100%
percent yield = (8.82 g / 6.87 g) * 100%
percent yield ≈ 128.3%
Since the percent yield should not exceed 100%, the answer is e) unknown as there is not enough data to determine the percent yield.