Ch.3 - Chemical ReactionsWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds
Jules Bruno

The percent yield of your chemical reaction represents how efficiently the reactants can be transformed into products. A larger percent yield means more product(s) have been formed. 

Where do we begin? 

Before you can calculate your percent yield you must first use stoichiometry and a balanced equation to determine the theoretical yield of the limiting reactant.

I'll be showing you how to solve these types of problems using a very common example question: 

"If 45.0 g benzene reacts with excess oxygen to produce 112 g carbon dioxide, what is the percent yield of the reaction?"  

Balanced-Chemical-EquationBalanced Chemical Equation

Within our calculations we will ignore both oxygen and water because they are either in excess or not addressed within the question.  

STEP 1: Calculate the molar masses of C6H­­6 and CO2

How-to-find-molar-massCalculating Molecular Weights or Molar Masses

STEP 2: Convert the grams of C6H6 into moles of C6H­6

Transform-given-grams-to-molesConversion from grams to molesSTEP 3: Convert the moles of C6Hinto moles of CO2 by doing a mole-to-mole ratio. 

Balanced-Chemical-EquationBalanced Chemical Equation

Bring down the coefficients from the balanced equation. 

Mole-to-Mole-RatioMole to Mole Ratio

STEP 4: Convert the moles of CO­2 into grams of CO2

Conversion-from-moles-to-gramsConversion from moles to grams

STEP 5: Calculate the percent yield. 

Percent-Yield-Formula-CalculatorPercent Yield Formula

The actual yield represents the amount of product that is made, isolated or produced when doing the reaction in real life. The actual yield would be the 112 grams of carbon dioxide. 

Calculating-Percent-YieldCalculating Percent Yield

The theoretical yield represents the maximum amount of product that could be made, but in reality we never obtain that amount. Some product is always lost through isolation, purification, transfer or some other uncontrollable variable. 

Calculations involving experimental error or percent error. 

Percent-Error-Actual-Yield-Experimental-YieldPercent Error Formula

The larger the percent error value then the less precise our calculations. 

Calculating-Percent-ErrorCalculating Percent Error

Percent recovery deals with the purification of a chemical sample. 

Percent-RecoveryPercent RecoveryIf hypothetically our 112 grams of carbon dioxide was expelled from 546 grams of sedimentary rock.

Calculating-Percent-RecoveryCalculating Percent Recovery

Jules Bruno

Jules felt a void in his life after his English degree from Duke, so he started tutoring in 2007 and got a B.S. in Chemistry from FIU. He’s exceptionally skilled at making concepts dead simple and helping students in covalent bonds of knowledge.