# how do you find percentage yield???

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#1
how do you find the percentage yield of something? i made
0.33g of aspirin before recrystallisation
0.12g of aspirin after recrystallisation
I used 4cm3 of ethanoic anhydride
2.0g of 2-hydroxybenzenecarboxylic acid

what is my theoretical yield, actual yield and percentage yield?
0
1 year ago
#2
(Original post by i.hate.gcses)
how do you find the percentage yield of something? i made
0.33g of aspirin before recrystallisation
0.12g of aspirin after recrystallisation
I used 4cm3 of ethanoic anhydride
2.0g of 2-hydroxybenzenecarboxylic acid

what is my theoretical yield, actual yield and percentage yield?
If your reaction is perfect you get 100% yield. You work this out from the moles of the limiting reagent used ==> moles of product ==> mass of product.
actual yield is the mass of product
percentage yield is (actual/theoretical)*100
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#3
im rubbish when It comes to moles
0
1 year ago
#4
Your TY is calculated using the moles of 2-hydroxybenzenoic acid.
As the molar ratio of the acid to aspirin is 1:1. You assume you form 2g if aspirin. Using this mass you calculate moles: moles=mass/mr

Then calculate PY=AT/TY
1
#5
(Original post by tangoboy456)
Your TY is calculated using the moles of 2-hydroxybenzenoic acid.
As the molar ratio of the acid to aspirin is 1:1. You assume you form 2g if aspirin. Using this mass you calculate moles: moles=mass/mr

Then calculate PY=AT/TY
wow thank you so much!
0
#6
(Original post by tangoboy456)
Your TY is calculated using the moles of 2-hydroxybenzenoic acid.
As the molar ratio of the acid to aspirin is 1:1. You assume you form 2g if aspirin. Using this mass you calculate moles: moles=mass/mr

Then calculate PY=AT/TY
How about if i'm trying to find the percentage yield of the aspirin before recrystallisation
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#7
I don't get how to find the mass and mr of the aspirin also do I find the moles of the 2-hydroxybenzoic acid using that equation aswell?
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#8
can someone please do it for me I really need help! its for my assignment thats due in a few hours!!!
0
1 year ago
#9
(Original post by i.hate.gcses)
How about if i'm trying to find the percentage yield of the aspirin before recrystallisation
Then your actual yield is the mass of aspirin before recrystallisation. Which is 0.33g
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#10
(Original post by tangoboy456)
Then your actual yield is the mass of aspirin before recrystallisation. Which is 0.33g
thank you. I still don't get the mr and moles stuff. could you work it out for me? I really need to complete it by the end of the day
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