PercentYield

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Percent Yield

As when your Mother make cookies, she determines how many dozen cookies she wants and then looks at her recipe to determine how much of flour, eggs, etc. (we call them reactants) she needs to mix together (we call it react) to obtain that exact number of dozen of cookies.

Of course, some of the cookie dough does not always get into the oven to be made into cookies (Gremlins eat it I heard), (we call it yield), so she does not always get exactly the number of dozen cookies as she expected. So she usually gets an actual number of dozen (we call it actual yield) compared to what she calculated in her recipe (we call it theoretical yield).

The closer the number of dozens she gets to the number she calculated she would get, the happier she is.

Of course, chemist have a name for all this, it is called Percent Yield.

In real life, other chemical reactions occur besides the one we want to occur. These side reactions consume the reactant but do not make products that we desire. Therefore we do not actually get (called actual yield) all the products that we would expect to get (we call theoretical yield). The percent yield is how close you come to what you wanted to get and can be calculated by the following equation:

Percent Yield = [(Actual yield) / (Theoretical yield) ]X [100%]

Actual yield - mass of products you experimentally obtained

Theoretical yield - mass of products you calculated to get

Remember - Percent Yield are only for PRODUCTS, never for reactants


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Last edited March 2, 2015 10:24 am (diff)
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