Percent Yield!!!!

Theoretical yield is basically the amount of a substance that should be produced from a chemical reaction. So if you have x amount of H and x amount of O, how much H2O will be produced?

Percent yield however is based on the actual amount that is produced, versus the theoretical amount. So percent yield is like a measure of how successful your experiment is.

The equation for percent yield is :  Experimental x 100
                                                    Theoretical
Lets try some examples:

Ex 1.  The production of Copper(II) Chloride is given by the equation:
                     
                                       FeCl2 + Cu = Fe + CuCl2

If 34.5g of Copper(II) Chloride and 4g of Copper(II) are produced, determine the theoretical yield of Copper(II).


34.5x   1mol  x 1 x 63.5 = 16.3g
         134.5g    1    1mol

 Percent Yield = 4g x100 =  24%
                          16.3g

Ex 2.  Hydrogen is reacted with Oxygen to produce water. If 1.6 mol of Hydrogen are reacted and 32g of water is produced, what is the theoretical yeild of water?

               2H2 + O2 = 2H2O

1.6mol H2 x 2 x 18g  = 28.8g
                   2    1mol

Percent Yield = 28.8 x100= 90% yield
                         32



And that, Ladies and Gentlemen, is Percent Yield.