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You are watching: Can a percent yield be over 100


I am in search of a basic answer; nopoint as well detailed. And no. This is not a homejob-related question. It happened to me in lab and also I am wondering what error I can have actually committed.


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Preface: The trouble is that you have actually overproclaimed your portion yield, and also the symptom is that it is over 100%.

Example: You and also your frifinish each carry out an experiment wright here the literary works claims the yield should be ~65%. You both use bad method and fail to dry your product, bring about you to attribute water mass as product mass. Your friend"s yield is 101%, and yours is 99%. Both you and also your frifinish are wrong, for the exact same reason! Don"t make the mistake of protecting against your evaluation as soon as portion yield drops below 100%. Don"t chastise your friend for having an "impossible" yield while patting yourself on the ago for your "99%"!

Overstatement of portion yield happens for the following reasons:

Zero) Your design of the reaction slrfc.org is just wrong. Unlikely in an undergraduate setting, but worth stating.

1) Your math is wrong. Worth double checking and straightforward to rule out as a resource of error.

2) You supplied even more reactant than you assumed. Most errors in reactant measurement cause you to use much less reactant than tape-recorded (e.g. transfer errors, impure reactants), yet you might maybe have supplied even more than you thought. Beyond basic measurement errors, perhaps your limiting reagent was gave to you in solution, and that solution was of better concentration than reported. Placed a little of time right into thinking about this, however protocols generally minimize the possibility of this sort of error.

3) You actually have actually much less product than you think.

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This is the many likely culprit. You have to be really hocolony with yourself right here. In most experiments, you take the mass of somepoint at the end, and also call it the mass of your product. Is it really your product? Or does that mass contain impurities which cause you to misreexisting impurities as product. Likely culprits are solvents (e.g. water from imcorrect drying), side-commodities, and/or unreacted reagent. Have you really done your best to filter and also remove them? If not, your yield will be inflated.