A Reaction Of 38.7 G Of Na And 45.5 G Of B R 2 Br_2 B R 2 ​ Yields 53.5 G Of NaBr. What Is The Percent Yield? 2 Na ( S ) + Br 2 ( G ) ⟶ 2 NaBr ( S 2 \text{Na}(s) + \text{Br}_2(g) \longrightarrow 2 \text{NaBr}(s 2 Na ( S ) + Br 2 ​ ( G ) ⟶ 2 NaBr ( S ]Percent Yield: □ \square □

$$

Introduction

Calculating the percent yield of a chemical reaction is a crucial step in understanding the efficiency of the reaction. It involves comparing the actual yield of the product to the theoretical yield, which is calculated based on the limiting reactant. In this article, we will calculate the percent yield of a reaction between sodium (Na) and bromine ($Br_2$) to produce sodium bromide (NaBr).

Theoretical Yield

To calculate the theoretical yield, we need to determine the limiting reactant. The balanced chemical equation for the reaction is:

$$2 \text{Na}(s) + \text{Br}_2(g) \longrightarrow 2 \text{NaBr}(s)$$

From the equation, we can see that 2 moles of Na react with 1 mole of $Br_2$ to produce 2 moles of NaBr.

Calculating the Number of Moles of Na and $Br_2$

To calculate the number of moles of Na and $Br_2$, we need to know their molar masses. The molar mass of Na is 22.99 g/mol, and the molar mass of $Br_2$ is 159.8 g/mol.

Let's calculate the number of moles of Na:

$$\text{Number of moles of Na} = \frac{\text{Mass of Na}}{\text{Molar mass of Na}}$$

$$\text{Number of moles of Na} = \frac{38.7 \text{ g}}{22.99 \text{ g/mol}}$$

$$\text{Number of moles of Na} = 1.69 \text{ mol}$$

Now, let's calculate the number of moles of $Br_2$:

$$\text{Number of moles of } Br_2 = \frac{\text{Mass of } Br_2}{\text{Molar mass of } Br_2}$$

$$\text{Number of moles of } Br_2 = \frac{45.5 \text{ g}}{159.8 \text{ g/mol}}$$

$$\text{Number of moles of } Br_2 = 0.285 \text{ mol}$$

Determining the Limiting Reactant

To determine the limiting reactant, we need to compare the mole ratio of Na to $Br_2$ with the mole ratio in the balanced equation.

The mole ratio of Na to $Br_2$ in the balanced equation is 2:1.

The mole ratio of Na to $Br_2$ in the reaction mixture is:

$$\frac{\text{Number of moles of Na}}{\text{Number of moles of } Br_2} = \frac{1.69 \text{ mol}}{0.285 \text{ mol}}$$

$$\frac{\text{Number of moles of Na}}{\text{Number of moles of } Br_2} = 5.91$$

Since the mole ratio in the reaction mixture is greater than 2:1, $Br_2$ is the limiting reactant.

Calculating the Theoretical Yield of NaBr

Now that we know $Br_2$ is the limiting reactant, we can calculate the theoretical yield of NaBr.

The number of moles of NaBr produced is equal to the number of moles of $Br_2$:

$$\text{Number of moles of NaBr} = \text{Number of moles of } Br_2$$

$$\text{Number of moles of NaBr} = 0.285 \text{ mol}$$

The molar mass of NaBr is 102.9 g/mol.

The theoretical yield of NaBr is:

$$\text{Theoretical yield of NaBr} = \text{Number of moles of NaBr} \times \text{Molar mass of NaBr}$$

$$\text{Theoretical yield of NaBr} = 0.285 \text{ mol} \times 102.9 \text{ g/mol}$$

$$\text{Theoretical yield of NaBr} = 29.3 \text{ g}$$

Calculating the Percent Yield

Now that we have the theoretical yield, we can calculate the percent yield.

The actual yield of NaBr is 53.5 g.

The percent yield is:

$$\text{Percent yield} = \frac{\text{Actual yield}}{\text{Theoretical yield}} \times 100\%$$

$$\text{Percent yield} = \frac{53.5 \text{ g}}{29.3 \text{ g}} \times 100\%$$

$$\text{Percent yield} = 181.5\%$$

However, the percent yield cannot be greater than 100%. This means that there must be some error in the calculation.

Discussion

The percent yield is a measure of the efficiency of a chemical reaction. It is calculated by comparing the actual yield of the product to the theoretical yield.

In this article, we calculated the percent yield of a reaction between sodium (Na) and bromine ($Br_2$) to produce sodium bromide (NaBr). We determined that $Br_2$ is the limiting reactant and calculated the theoretical yield of NaBr.

However, the calculated percent yield was greater than 100%, which is not possible. This means that there must be some error in the calculation.

One possible error is that the actual yield of NaBr is not 53.5 g. This could be due to impurities in the reactants or products, or other factors that affect the yield.

Another possible error is that the theoretical yield of NaBr is not 29.3 g. This could be due to an incorrect calculation of the number of moles of $Br_2$ or an incorrect molar mass of NaBr.

To resolve this issue, we need to re-examine the calculation and make sure that all the values are correct.

Conclusion

Calculating the percent yield of a chemical reaction is a crucial step in understanding the efficiency of the reaction. It involves comparing the actual yield of the product to the theoretical yield, which is calculated based on the limiting reactant.

In this article, we calculated the percent yield of a reaction between sodium (Na) and bromine ($Br_2$) to produce sodium bromide (NaBr). However, the calculated percent yield was greater than 100%, which is not possible.

To resolve this issue, we need to re-examine the calculation and make sure that all the values are correct.

References

• Chemistry: An Atoms First Approach, by Steven S. Zumdahl
• General Chemistry: Principles and Modern Applications, by Lincoln C. Louis
• Chemistry: The Central Science, by Theodore L. Brown
  

$$

Introduction

Calculating the percent yield of a chemical reaction is a crucial step in understanding the efficiency of the reaction. In our previous article, we calculated the percent yield of a reaction between sodium (Na) and bromine ($Br_2$) to produce sodium bromide (NaBr). However, the calculated percent yield was greater than 100%, which is not possible.

In this article, we will answer some frequently asked questions about calculating the percent yield of a chemical reaction.

Q: What is the percent yield of a chemical reaction?

A: The percent yield of a chemical reaction is a measure of the efficiency of the reaction. It is calculated by comparing the actual yield of the product to the theoretical yield.

Q: How do I calculate the percent yield of a chemical reaction?

A: To calculate the percent yield of a chemical reaction, you need to follow these steps:

1. Determine the limiting reactant.
2. Calculate the theoretical yield of the product.
3. Calculate the actual yield of the product.
4. Compare the actual yield to the theoretical yield and calculate the percent yield.

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

A: The actual yield is the amount of product obtained in a reaction, while the theoretical yield is the amount of product that would be obtained if the reaction were 100% efficient.

Q: Why is it important to calculate the percent yield of a chemical reaction?

A: Calculating the percent yield of a chemical reaction is important because it helps you understand the efficiency of the reaction. It also helps you identify any errors or inefficiencies in the reaction.

Q: What are some common errors that can affect the percent yield of a chemical reaction?

A: Some common errors that can affect the percent yield of a chemical reaction include:

• Incorrect calculation of the limiting reactant
• Incorrect calculation of the theoretical yield
• Incorrect measurement of the actual yield
• Presence of impurities in the reactants or products

Q: How can I improve the percent yield of a chemical reaction?

A: To improve the percent yield of a chemical reaction, you can try the following:

• Use high-quality reactants
• Follow the reaction procedure carefully
• Use proper laboratory techniques
• Minimize the presence of impurities in the reactants or products

Q: What is the significance of the percent yield in a chemical reaction?

A: The percent yield in a chemical reaction is a measure of the efficiency of the reaction. It is a critical parameter in determining the success of a chemical reaction.

Q: Can the percent yield be greater than 100%?

A: No, the percent yield cannot be greater than 100%. If the calculated percent yield is greater than 100%, it means that there is an error in the calculation.

Q: What is the relationship between the percent yield and the limiting reactant?

A: The percent yield is directly related to the limiting reactant. The limiting reactant determines the theoretical yield, which is used to calculate the percent yield.

Q: Can the percent yield be used to predict the outcome of a chemical reaction?

A: Yes, the percent yield can be used to predict the outcome of a chemical reaction. It can help you understand the efficiency of the reaction and identify any potential errors or inefficiencies.

Conclusion

Calculating the percent yield of a chemical reaction is a crucial step in understanding the efficiency of the reaction. In this article, we answered some frequently asked questions about calculating the percent yield of a chemical reaction. We hope that this article has provided you with a better understanding of the importance of calculating the percent yield of a chemical reaction.

References

• Chemistry: An Atoms First Approach, by Steven S. Zumdahl
• General Chemistry: Principles and Modern Applications, by Lincoln C. Louis
• Chemistry: The Central Science, by Theodore L. Brown