How to Calculate Theoretical Yield and Percent Yield

TL;DR

To calculate the theoretical yield, balance the chemical equation and identify the limiting reactant. Use the formula for percent yield: (actual yield / theoretical yield) x 100%. The actual yield is the amount obtained from the experiment, while the theoretical yield is the maximum potential based on the balanced reaction.

Transcript

in this video we are going to talk about how to calculate the theoretical and percent yield of a compound so the first thing we need to do is write a balanced chemical equation so we have c3h8 which stands for propane and it's burning air so it's going to react with oxygen gas and it's going to produce carbon dioxide and the other product is water ... Read More

Key Insights

• 🫀 Balancing a combustion reaction involves starting with carbon atoms, then hydrogen atoms, and finally oxygen atoms.
• 💆 The theoretical yield is calculated based on the starting material's mass and the balanced chemical equation.
• ❓ The actual yield is the amount of product obtained in the experiment and is usually given in a problem.
• ❓ The percent yield is calculated by comparing the actual yield to the theoretical yield.
• 😒 It is important to use the limiting reactant when calculating the percent yield.
• ❓ The percent yield represents the efficiency of the reaction and is always less than 100 percent.
• 🧑‍🏭 The percent yield can be used to determine the success of a reaction or to identify factors that may have affected the yield.

Questions & Answers

Q: What is the first step in calculating the theoretical and percent yield of a compound?

The first step is to write a balanced chemical equation for the reaction.

Q: Why is it important to balance the carbon atoms in a combustion reaction first?

Balancing the carbon atoms first ensures that the equation follows the law of conservation of mass.

Q: How do you determine the limiting reactant in a reaction?

The limiting reactant is the reactant that is completely consumed and determines the amount of product that can be formed.

Q: What is the difference between theoretical and actual yield?

Theoretical yield is the maximum amount of product that can be obtained, while the actual yield is the amount obtained in the experiment.

Q: How do you calculate the theoretical yield?

The theoretical yield can be calculated by converting the mass of the starting material to the moles of the product using the balanced chemical equation and molar ratios.

Q: How is the percent yield calculated?

The percent yield is calculated by dividing the actual yield by the theoretical yield and multiplying by 100 percent.

Q: Why is the actual yield usually given in a problem?

The actual yield is usually given in a problem because it represents the experimental result, whereas the theoretical yield is calculated based on ideal conditions.

Q: Why is it important to use the limiting reactant when calculating the percent yield?

The limiting reactant determines the maximum amount of product that can be formed, so using it to calculate the percent yield provides a more accurate representation of the reaction efficiency.

Summary & Key Takeaways

• To calculate the theoretical and percent yield of a compound, start by balancing the chemical equation.

• Identify the limiting reactant and the excess reactant.

• The theoretical yield is the maximum amount of product that can be obtained, while the actual yield is the amount obtained in the experiment.

• Use the actual and theoretical yield to calculate the percent yield.