Understanding Theoretical and Percent Yield in Combustion Reactions

This video tutorial explains how to calculate the theoretical and percent yield in a chemical reaction. It begins with writing and balancing a combustion reaction involving propane and oxygen. The tutorial then details the steps to balance carbon, hydrogen, and oxygen atoms. It explains the difference between actual and theoretical yield and provides a formula for calculating percent yield. The video concludes with a step-by-step calculation of the theoretical yield of CO2 and the final percent yield.

What is the first step in solving the problem involving propane and air?

• Measure the actual yield

• Identify the limiting reactant

• Write a balanced chemical equation

• Calculate the percent yield

In balancing combustion reactions, which element should be balanced last?

• Hydrogen

• Carbon

• Nitrogen

• Oxygen

What does the percent yield formula compare?

• Temperature to pressure

• Theoretical yield to actual yield

• Reactants to products

• Mass to volume

What is the role of the limiting reactant in a chemical reaction?

• It determines the maximum amount of product formed

• It is always present in excess

• It does not affect the reaction

• It is the reactant with the highest molar mass

How do you convert grams of a reactant to moles?

• Use the molar mass

• Use the density

• Use the boiling point

• Use the atomic number

What is the molar mass of propane (C3H8)?

• 1.008 grams per mole

• 44.094 grams per mole

• 12.01 grams per mole

• 16.00 grams per mole

How many moles of CO2 are produced from one mole of propane?

• One mole

• Two moles

• Three moles

• Four moles

What is the theoretical yield of CO2 when 30 grams of propane is burned?

• 89 grams

• 70 grams

• 100 grams

• 44 grams

What is the percent yield if the actual yield is 70 grams and the theoretical yield is 89 grams?

• 90%

• 85%

• 80%

• 77.9%

Why is oxygen considered the excess reactant in this reaction?

• It is not involved in the reaction

• It is abundant in the air

• It is present in a limited amount

• It has a higher molar mass than propane