Theoretical yield...?

Question

a) Define the terms theoretical yield, actual yield, and percent yield.

b) What us the actual yield in a reaction almost always less than the theoretical yield?

Thanks for the help

10 points

Answer 1

Theoretical Yield

    * this is how much product will be synthesized in ideal conditions.

Actual Yield



    * this is how much product was actually synthesized in an experiment.

Percent Yield

    * The percentage yield is the ratio between the actual yield and the theoretical yield multiplied by 100%.  It indicates the percent of theoretical yield that was obtained from the final product in an experiment.  

    * The percentage yield can be calculated using the mass of the actual product obtained and the theoretical mass of the product calculated using the balanced equation of the reaction.



Percentage Yield =    (Mass of Actual Yield)/(Mass of Theoretical Yield)   x   100%

Answer 2

a) Theoretical yield is how much product you should get if your reaction went to completion.

Actual yield is how much product you obtain when you do your experiment

Percent yield is (actual yield / theoretical yield) x 100

b) Not all reactions go fully to completion. Combustion reactions tend to do so in the presence of excess oxygen, but many others form some sort of equilibrium, which means some of your reactants remain. If you are collecting a precipitate, it is easy to lose a little.  Also, most solids will have a least a tiny solubility in water, so you will not collect quite as much as theory states you could.  Human/experimental errors are also common.