Theoretical Yield and Percentage Yield of Organic Molecules

• Chemistry
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In summary, a student investigated several esters, and made octyl acetate. The student used the acid derivative, acetyl chloride (as you saw decanedioyl dichloride used to make 6,10 nylon) and 1-octanol. Using the following information, the student calculated the theoretical yield for the aspirin synthesis.
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Homework Statement

1. A student investigated several esters, and made octyl acetate, an ester with the fragrance of oranges. The student used the acid derivative, acetyl chloride (as you saw decanedioyl dichloride used to make 6,10 nylon) and 1-octanol. Using the following information, calculate the theoretical yield for the student. (Hint: you need to calculate the molar masses and to identify the limiting reagent).

Structural Equation

Quantities used:

acetyl chloride: 0.654 g

1-octanol: 1.401 g.

Calculate theoretical yield. Enter your answer with three significant figures in grams.

2.
A student began the aspirin synthesis with 2.083 g salicylic acid and excess acetic anhydride. The student's actual weighed yield was 2.534 g. Calculate the % yield. Give your answer as % with 3 significant figures (that is 1 decimal place in your %age). Do not include % symbol.

Homework Equations

Percentage Yield = Actual yield/theoretical yield

The Attempt at a Solution

1. I figured out the equation: C8H18O + CH3COCl ----> C10H20O2 + HCL (1:1 Ratio)
Figuring out the moles for 1-octanol and acetyl chloride gives me acetyl chloride as the limiting reagent with 0.00833moles. Multiplying this with the molar mass of octyl acetate gives me 1.44g. Is this right?

2. Once again we have a 1:1 ratio. We are given that salicylic acid is the limiting reagent. 2.083/138.13 = 0.0150 moles theoretically of aspirin. 0.0150mol x molar mass aspirin (180.17g/mol) = 2.7169g.
2.534/2.7169 = 93.3%.
Thanks for the help, I think my answers are right but I normally get something simple wrong.

Last edited:
Your images don't show for us.

Yes, acetyl chloride is a limiting reagent, yes 1.44 g of octyl acetate looks OK.

Sorry about that, think I fixed it now

Second image has nothing to do with the reaction from the question.

Other than that logic looks good.

THANKYOU SO MUCH! I am studying for an exam at the moment and this helped me so much!

Cheers fam :)

1. What is theoretical yield?

Theoretical yield is the maximum amount of product that can be produced in a chemical reaction, based on the amount of limiting reactant present and assuming 100% conversion of all reactants to products.

2. How is theoretical yield calculated?

Theoretical yield is calculated using stoichiometry, which involves converting the moles of the limiting reactant to moles of the product using the mole ratio from the balanced chemical equation.

3. What is percentage yield?

Percentage yield is the actual amount of product obtained in a chemical reaction, expressed as a percentage of the theoretical yield.

4. How is percentage yield calculated?

Percentage yield is calculated by dividing the actual yield (amount of product obtained) by the theoretical yield and multiplying by 100%.

5. What factors can affect the percentage yield of a reaction?

The percentage yield of a reaction can be affected by human error, impurities in reactants, side reactions, and incomplete conversion of reactants to products.

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