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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: tropicanapure on November 03, 2006, 01:48:04 PM

Title: yield calc including unchanged molecule
Post by: tropicanapure on November 03, 2006, 01:48:04 PM
hey, I was wondering if someone could straighten something out for me, i know there's alot of yield calculation threads but it's really confusin me.. say you have a selective borohydride reduction of a kethone to an alcohol, and the molecule that isnt reduced is an ester. would you have to include the ester in the yield calculations for the alcohol, even though the ester is unchanged in the reaction as i worked out it was the limiting reagent.  If not is the theoretical yield of the ester just then 100%?


2-pentanol + MeOH + methyl benzoate +  H20   ---> 2-pentanone + methyl benzoate + MeONa + BH3

Material             RMM        amount   moles    Mole ratio
2-pentanone       86.13   10 g       0.116   2.3
Methyl benzoate       136.15   7g       0.0514   1
Sodium borohydride 37.83   4.1g     0.108         2.1
Methanol      20 ml           -    -                -
Water                9 ml            -      -                -

 Theres the equation etc, just put it in to see if it helped anyone understand my babbeling..thanks