if you used 40 g of cyclohexanol and obtained 24.6g of pure cyclohexene,
a) what is your w/w yield?
b) what is your theory yield?
Thank you !
If that reaction is 1:1 (1 mol cyclohanol gives 1 mol cyclohexene and I think it does), then
mols cyclohexanol = grams/molar mass = ?
mols cyclohexene = same
g cyclohexene = mols x molar mass = ?. This yield in grams in the theoretical yield (TY) and is the answer to part b.
I think part a question is not stated properly. I assume you want percent yield. That is (24.6/TY)*100 = ?
Technically, I think the yield is the 24.6 g. If you want percent yield you should ask for percent yield. Actually, I don't know what the term w/w means except when I quote a mass percent I usually write something like 12.0% w/w meaning 12.0 mass percent.
To calculate the w/w (weight/weight) yield and theoretical yield, you need to use the following formulas:
a) W/W Yield = (Actual yield / Initial amount) * 100%
b) Theoretical Yield = The maximum amount of product that could be obtained based on stoichiometry and the limiting reagent.
In this case, cyclohexanol is being converted to cyclohexene. The balanced chemical equation for this reaction is:
Cyclohexanol (C6H12O) → Cyclohexene (C6H10) + H2O
a) To calculate the w/w yield, you will divide the mass of the actual yield (24.6 g) by the initial amount of cyclohexanol used (40 g) and multiply by 100%:
W/W Yield = (24.6 g / 40 g) * 100% = 61.5%
b) To determine the theoretical yield, you need to find the limiting reagent. This is the reactant that is completely consumed during the reaction and limits the amount of product that can be formed. To find the limiting reagent, you compare the initial moles of each reactant to their stoichiometric coefficients.
The molar mass of cyclohexanol (C6H12O) is 100.16 g/mol. By dividing the mass of cyclohexanol used (40 g) by its molar mass, you can find the initial moles:
Initial moles of cyclohexanol = 40 g / 100.16 g/mol ≈ 0.3998 mol
Using the stoichiometry of the balanced equation, you can compare the moles of cyclohexanol to the theoretical moles of cyclohexene:
1 mol cyclohexanol ↔ 1 mol cyclohexene
Since the stoichiometric ratio is 1:1, the theoretical moles of cyclohexene would also be approximately 0.3998 mol.
The molar mass of cyclohexene (C6H10) is 82.15 g/mol. By multiplying the theoretical moles of cyclohexene by its molar mass, you can calculate the theoretical yield:
Theoretical Yield = 0.3998 mol * 82.15 g/mol ≈ 32.8 g
Therefore, the theory yield is approximately 32.8 g.
To summarize:
a) The w/w yield is approximately 61.5%.
b) The theoretical yield is approximately 32.8 g.