Calculating Percent Yield in Chemical Reactions

This video tutorial, part of a stoichiometry series, explains how to calculate and understand theoretical yield, actual yield, and percent yield in chemical reactions. Using a peanut butter and jelly sandwich analogy, the tutorial simplifies these concepts and demonstrates calculations with a real chemical reaction involving potassium chlorate. It also discusses factors that can affect yield and provides tips for accurate calculations.

What is the theoretical yield in chemistry?

• The efficiency of a chemical reaction

• The amount of reactant used in a reaction

• The maximum amount of product you can make with what you have

• The amount of product actually made and collected

How is the percent yield calculated?

• Actual yield divided by theoretical yield, multiplied by 100

• Theoretical yield divided by actual yield, multiplied by 100

• Actual yield multiplied by theoretical yield, divided by 100

• Theoretical yield multiplied by actual yield, divided by 100

What are the products of the decomposition of potassium chlorate?

• Potassium oxide and chlorine gas

• Potassium chloride and oxygen gas

• Potassium chloride and water

• Potassium and chlorine gas

Why is manganese(IV) oxide added to the decomposition reaction of potassium chlorate?

• To increase the yield of potassium chloride

• To balance the chemical equation

• To act as a reactant

• To speed up the reaction without being changed itself

What is the molar mass of potassium chlorate (KClO3)?

• 58.5 grams per mole

• 74.5 grams per mole

• 122.5 grams per mole

• 32 grams per mole

In the stoichiometry calculation, what is the first step?

• Writing down the mass of the reactant

• Balancing the chemical equation

• Writing down the mass of the product

• Calculating the molar mass of the product

What was the theoretical yield of oxygen gas in the given reaction?

• 32 grams

• 3.92 grams

• 10.0 grams

• 3.41 grams

What was the actual yield of oxygen gas collected in the lab?

• 10.0 grams

• 3.41 grams

• 32 grams

• 3.92 grams

Why is the actual yield usually less than the theoretical yield?

• Side reactions may occur

• The reactant is always fully converted to product

• The product is always pure

• The reaction is always complete

What does it indicate if the actual yield is more than the theoretical yield?

• The reaction was very efficient

• There was a mistake in the experiment

• The reactant was fully converted to product

• The product was very pure