Chemistry Theoretical Yield and Percentage Yield of Organic Molecules

AI Thread Summary
The discussion revolves around calculating the theoretical yield of octyl acetate from a reaction involving acetyl chloride and 1-octanol, identifying acetyl chloride as the limiting reagent, resulting in a theoretical yield of 1.44 grams. Additionally, the percentage yield of aspirin synthesis from salicylic acid and acetic anhydride is calculated, yielding a percentage of 93.3%. The calculations for both reactions are confirmed to be correct, with the participants expressing gratitude for the assistance provided. The conversation highlights the importance of accurately determining limiting reagents and yields in organic chemistry experiments. Overall, the thread serves as a valuable resource for students preparing for exams in organic chemistry.
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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
tcc6aZC.png


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.

UuJb1st.png

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.
 
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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.
 
That's embarrassing! Sorry about that.
 
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 :)
 
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