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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: 87mustang on April 04, 2008, 07:13:08 PM

Title: extra credit please help need the points
Post by: 87mustang on April 04, 2008, 07:13:08 PM
The aspirin substitute acetaminophen (C8H9O2N) is produce by the following three-step synthesis:

1) C6H5O3N(s) + 3H2 (g) + HCI(aq) >>> C6H8ONCI(s) + 2H2O(l)

2) C6H8ONCI(s) + NaOH(aq)>>>  C6H7ON(s)+ H2O(l) + NaCl(S)

3) C6H7ON(s) + C4H6O3(l)>>>  C8H9O2N(s)  +  HC2H3O2(l)

The first two reactions have percent yields of 87% and 98% by mass, respectively. The overall reaction yields 3 mol of acetaminophen product, C8H9O2N, for every 4 mol of C6H5O3N reacted.

a) what is the percent yield by mass for the overall process?

b)what is the percent yield by mass of step 3?

how do i go about doing this? i dont even know where to start? she might try and trick us to with unbalanced equations.
PLEASE HELP ME!!!!
Title: Re: extra credit please help need the points
Post by: Arkcon on April 04, 2008, 07:25:55 PM
she might try and trick us to with unbalanced equations.


OK, so make sure they're balanced first.  Same number of each atom on each side.  Don't assume, just because it's extra credit, she'll trick you that way -- she might be more creative than that ;).

Quote
The first two reactions have percent yields of 87% and 98% by mass, respectively. The overall reaction yields 3 mol of acetaminophen product, C8H9O2N, for every 4 mol of C6H5O3N reacted.

a) what is the percent yield by mass for the overall process?

b)what is the percent yield by mass of step 3?


how do i go about doing this? i dont even know where to start?PLEASE HELP ME!!!!

Not a big problem.  Just work on it a little at a time.  They give you totals of start to finish, so you can determine % yield.  And the % yield of two steps, so you can figure out the third.
Title: Re: extra credit please help need the points
Post by: 87mustang on April 04, 2008, 07:42:49 PM
im not positive but to me the look balanced, im not good at chemistry that why im asking for some help, i dont just want the answer i want to know how to do it in case i get call out in class
Title: Re: extra credit please help need the points
Post by: Borek on April 05, 2008, 02:17:48 AM
3 x balanced.