Theoretical Yield and Percentage Yield of Organic Molecules

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Discussion Overview

The discussion revolves around the calculation of theoretical yield and percentage yield in organic chemistry, specifically focusing on the synthesis of octyl acetate and aspirin. Participants engage in a homework problem that involves determining limiting reagents and applying relevant equations.

Discussion Character

  • Homework-related
  • Mathematical reasoning

Main Points Raised

  • A participant presents a homework problem involving the synthesis of octyl acetate and aspirin, detailing the quantities used and the need to identify the limiting reagent.
  • The participant calculates the theoretical yield of octyl acetate as 1.44 g, asserting that acetyl chloride is the limiting reagent.
  • The same participant calculates the percentage yield of aspirin as 93.3%, based on the actual yield and theoretical yield derived from the limiting reagent of salicylic acid.
  • Another participant confirms the calculation of acetyl chloride as the limiting reagent and agrees that the theoretical yield of octyl acetate appears correct.
  • There are comments regarding images not displaying properly, with one participant acknowledging the issue and attempting to rectify it.
  • One participant expresses gratitude for the assistance received, indicating that the discussion has been helpful for exam preparation.

Areas of Agreement / Disagreement

Participants generally agree on the calculations presented, particularly regarding the limiting reagent and theoretical yield for octyl acetate. However, there are no explicit statements of consensus on all aspects of the calculations, and some uncertainty remains regarding the accuracy of the images shared.

Contextual Notes

Participants rely on the assumption that the ratios and molar masses used in calculations are correct, but there is no detailed verification of these values within the discussion. The context of the images and their relevance to the problem remains unclear.

Who May Find This Useful

Students studying organic chemistry, particularly those preparing for exams involving yield calculations and limiting reagents in synthesis reactions.

fishes
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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.
 
Last edited:
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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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