Percent Yield

Percent Yield is the amount of product obtained in a chemical reaction
It can be determined by the masses used in a reaction and the mole ratios in the balanced equation.

A good website for self study:
http://www.chemcollective.org/stoich/percentyield.php

Example 1:

For the balanced equation shown below, if the reaction of 50.6 grams of Pb(NO₃)₂ produces a 74.2% yield, how many grams of PbO would be produced ?
2Pb(NO₃)₂=>2PbO+4NO₂+O₂

To answer this question, you use the mass ratio from the balanced equation to determine the theoretical yield.
theoretical yield of PbO:(mass of PbO)/(mass of Pb(NO₃)₂)*given mass
93.94/310*50.6=15.3
Multiplying the theoretical yield by the percent (and dividing by 100), provides the actual yield.
(theory*%yield)/100=actual yield
(15.3*74.2)/100=11.4

 

Example 2:

For the balanced equation shown below, if the reaction of 57.4 grams of N₂ produces 107 grams of Mg₃N₂, what is the percent yield?
3Mg+N₂=>Mg₃N₂

To answer this question, you use the mass ratio from the balanced equation to determine the theoretical yield.
theoretical yield of Mg₃N₂:(mass of Mg₃N₂)/(mass of N₂)*given mass
100.9/28.01*57.4=207
The percent yield is determined as follows:
(actual/theory)*100=%yield
(107/207)*100=51.5%

 

Example 3:

For the balanced equation shown below, if the reaction of 54.9 grams of C₂H₃O₂Cl produces 32.6 grams of CO₂, what is the percent yield?
4C₂H₃O₂Cl+7O₂=>8CO₂+6H₂O+2Cl₂

To answer this question, you use the mass ratio from the balanced equation to determine the theoretical yield.
theoretical yield of CO₂:(mass of CO₂)/(mass of C₂H₃O₂Cl)*given mass
352.08/378*54.9=51.1
The percent yield is determined as follows:
(actual/theory)*100=%yield
(32.6/51.1)*100=63.8%

Here is  video about the percent yield found on YouTuBe