Lecture: Solving Stoichiometry Problems

Core Concepts

• Understanding what stoichiometry is and different types of problems.
• Practice through examples to master stoichiometry.

Topics Covered in Other Articles

• Balancing Chemical Equations
• What is a Chemical Reaction?
• Calculating Molar Mass
• Percent Yield Calculation
• How to Calculate Molarity
• What Are Significant Figures

Stoichiometry Definition

What is Stoichiometry?

• Math related to chemical reactions.
• Involves calculations with moles, masses, and percentages.
• Stoichiometric Ratio: Relationship between coefficients of reactants and products for a normal reaction.

Stoichiometry Problems

Balancing Chemical Equations

• Importance: Correct ratio of reactants and products is crucial.
• Example: Balancing ( C_{2}H_{2} + O_{2} \rightarrow CO_{2} + H_{2}O )
  • Balanced equation: ( 2C_{2}H_{2} + 5O_{2} \rightarrow 4CO_{2} + 2H_{2}O )

Example Using Stoichiometric Ratio (Moles)

• Reaction: ( C_{6}H_{12}O_{6} \rightarrow 2C_{2}H_{5}OH + 2CO_{2} )
• Problem: How many moles of CO2 are produced from 2.5 mol of ( C_{6}H_{12}O_{6} )?
  • Solution through dimensional analysis: 5 mol of CO2._

Example Using Stoichiometric Ratio (Mass)

• Problem: How many grams of ( C_{6}H_{12}O_{6} ) was used if 10g of ( C_{2}H_{5}OH ) was produced?
  • Solution: 19.55g of ( C_{6}H_{12}O_{6} ).

Stoichiometry Practice Problems

Problem 1

• Reaction: ( CaCl_{2} + 2AgNO_{3} \rightarrow Ca(NO_{3})_{2} + 2AgCl )
• Question: How much AgCl (in grams) from 2.00 mol of ( CaCl_{2} )?
• Solution: 573g AgCl._

Problem 2

• Reaction: ( 2C_{6}H_{14} + 19O_{2} \rightarrow 12CO_{2} + 14H_{2}O )
• Question: How much hexane did you burn to produce 60 mol of gas?
• Solution: 99.4g of ( C_{6}H_{14} )._

Additional Resources

• Interactive lecture on stoichiometry problems.
• Video tutorial on solving reaction stoichiometry problems.

Further Reading

• Percent by Weight Calculation
• Balancing Redox Reactions
• How to Write Net Ionic Equations
• What is Specific Heat?
• Common Ion Effect