Question

What would be the effect of the following on the percentage yield of aspirin:
a. addition of dilute sulfuric acid instead of concentrated sulfuric acid
b. using a base (e.g. NaOH) instead of concentrated sulfuric acid
c. dissolving the crystals in hot water only

Answer 1

answer of option b is...
Aspirin is acetyl salycilic acid
The formula is C9H8O4
Acid + base >> salt + water
C9H8O4 + NaOH >> C9H7O4Na + H2O
we get sodium salycilate

Answer 2

so what is the effect of the base in the yield of aspirin? increase or decrease or something else?

Answer 3

i think it will increase here

Answer 4

why?

Answer 5

The percentage would decrease in all these because conc. H2SO4 is a strong acid and yields more and as compaired to a base and a weak acid..!

Answer 6

@aayushi.somani the sulfuric acid there is used as a catalyst in the reaction. can a catalyst really affect the percent yield of the product?

Answer 7

@aayushi.somani as far as i know, a catalyst only aids in the reaction rate. it is not being consumed up in the reaction. how would it affect the yield?

Answer 8

@agent0smith @Awesome781 @ams98 @aleisha96 @anqie37 @AverageJoe20

help me pls

Answer 9

@bookworm00981 @bibby @body @breerockzz @Bubbles1204

Answer 10

@cutepochacco @crescent1228

Answer 11

@Destinymasha @douglaswinslowcooper @damoss @Dianegrace

Answer 12

Wow. Relax on the Mentioning bro.

Answer 13

@emma97 @edoanhue96 @ganeshie8 @Geniu @hba @HelpBlahBlahBlah @heyyeahyou @Hokkoni @iheartos @idiotdancer @jojo4eva @Jasmina @jamielovesmickey @Jesstho.-. @jane.y @kirbykirby @katy1204 @Luigi0210 @linda3 @Lethal @LovelyAnna @lyanda @lyubas @michu @mamasherman @MotionlessInWhite1996 @Mashy @mlb004 @Opcode @ParthKohli @Preetha @PenguinLove_96 @person4505 @rochelle @ryanmwhite @RainbowBeefcake @ricesoup @SolomonZelman @shamil98 @SnuggieLad @studyislandhelp @Squirrels @sharon_penn @timo86m @TheSecretsToday @TheForbiddenFollower @tianadler help pls!

Answer 14

I guess he missed what I said...

Answer 15

@bookworm00981 sorry bout that. i just need someone to help me. i need to have answers by today

Answer 16

k

Answer 17

ahahaha... i'm sorry but i never studied Chemistry

Answer 18

I'm sorry! I haven't taken this stuff yet.

Answer 19

@linda3 @LovelyAnna it's ok :)

Answer 20

Hey @zaisav is ur name Savannah Pada?

Answer 21

yes. why?

Answer 22

Yes it is, I should have checked ur profile first lol.

Answer 23

Oh, I saw that you asked this on Yahoo, thats all. :P

Answer 24

The @bookworm00981 see's all

Answer 25

If you want the Answer you'll read this, it will help.
http://www.lahc.edu/classes/chemistry/arias/Exp%205%20-%20AspirinF11.pdf

Answer 26

What synthetic procedure did you follow?

Answer 27

@aaronq the one in which the starting materials are salicylic acid, acetic anhydride, and sulfuric acid as catalyst

Answer 28

since the acid is used as a catalyst, diluting it would not have a large effect on the yield (you're also making acetic acid in the process, although this acid is weak) Though, due to time constraints you'll get a poor yield.

If you use NaOH or any other strong base you'll get side reactions, like the cleavage of acetic anhydride into acetic acid, which will affect the yield negatively.

Not using a catalyst at all wouldn't be a good idea. The reaction can still occur (nucleophilic attack by OH of the phenyl on any of the carbonyl carbons of acetic anhydride), but it will take ages for you to get a decent yield.