Chemical Reaction Yields and Calculations

This video tutorial covers the concepts of limiting and excess reactants, how to balance combustion reactions, and methods to calculate theoretical and percent yield. It provides step-by-step instructions on identifying limiting reactants using mole ratios and calculating the amount of excess reactant left after a reaction. The tutorial includes examples with propane and benzene to illustrate these concepts.

What is the first step in solving a problem involving a combustion reaction?

• Calculate the percent yield

• Identify the limiting reactant

• Determine the excess reactant

• Write a balanced chemical equation

How do you determine the limiting reactant in a chemical reaction?

• By comparing the initial masses of reactants

• By measuring the final product mass

• By calculating the percent yield

• By dividing the moles of reactants by their coefficients

What is the theoretical yield of CO2 when 2 moles of propane react with 8 moles of oxygen?

• 3 moles

• 8 moles

• 4.8 moles

• 6 moles

If the actual yield of CO2 is 4.5 moles, what is the percent yield?

• 100%

• 95%

• 93.75%

• 90%

How do you calculate the amount of excess reactant left over?

• Subtract the amount that reacted from the initial amount

• Divide the initial amount by the amount that reacted

• Add the amount that reacted to the initial amount

• Multiply the initial amount by the percent yield

What is the first step in analyzing a new combustion reaction involving benzene?

• Write a balanced chemical equation

• Identify the excess reactant

• Calculate the percent yield

• Determine the actual yield

In the benzene combustion reaction, which reactant is the limiting reactant?

• Benzene

• Carbon dioxide

• Oxygen

• Water

What is the theoretical yield of water when 50 grams of benzene react completely?

• 40 grams

• 30 grams

• 34.6 grams

• 36 grams

How is the percent yield calculated in the benzene reaction?

• By adding the actual yield to the theoretical yield

• By subtracting the actual yield from the theoretical yield

• By dividing the theoretical yield by the actual yield and multiplying by 100

• By dividing the actual yield by the theoretical yield and multiplying by 100

How much of the excess reactant is left over after the benzene reaction?

• 50 grams

• 6.2 grams

• 153.07 grams

• 160 grams