Q1. Nitrogen And Hydrogen React To Form Ammonia.${ N_2(g) + 3 H_2(g) \Rightarrow 2 NH_3(g) } 12 C M 12 Cm 12 C M { ^3\$} Of Hydrogen Reacted With Excess Nitrogen To Form 2 Cm { ^3$}$ Of Ammonia.What Is The Percentage Yield Of Ammonia At

Introduction

In this problem, we will be dealing with the reaction between nitrogen and hydrogen to form ammonia. The balanced chemical equation for this reaction is:

${ N_2(g) + 3 H_2(g) \Rightarrow 2 NH_3(g) }$

We are given that 12 cm³ of hydrogen reacted with excess nitrogen to form 2 cm³ of ammonia. Our goal is to calculate the percentage yield of ammonia.

Theoretical Yield

To calculate the theoretical yield of ammonia, we need to use the concept of limiting reagents. In this case, we are given that hydrogen is the limiting reagent, and nitrogen is in excess.

The balanced chemical equation tells us that 3 moles of hydrogen react with 1 mole of nitrogen to form 2 moles of ammonia. We can use this information to calculate the number of moles of ammonia that should be formed.

First, we need to calculate the number of moles of hydrogen that reacted. We can do this by using the ideal gas law:

${ PV = nRT }$

where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature.

Since we are given the volume of hydrogen in cm³, we can use the following conversion factor:

${ 1 \, \text{cm}^3 = 10^{-6} \, \text{m}^3 }$

We can also assume that the temperature and pressure are constant, so we can cancel them out.

Rearranging the ideal gas law to solve for n, we get:

${ n = \frac{PV}{RT} }$

Substituting the values, we get:

${ n = \frac{(1 \, \text{atm})(12 \, \text{cm}^3)(10^{-6} \, \text{m}^3/\text{cm}^3)}{(0.0821 \, \text{L atm/mol K})(298 \, \text{K})} }$

Simplifying, we get:

${ n = 5.03 \times 10^{-4} \, \text{mol} }$

Now, we can use the balanced chemical equation to calculate the number of moles of ammonia that should be formed:

${ 2 \, \text{mol NH}_3 = 3 \, \text{mol H}_2 }$

So, the number of moles of ammonia that should be formed is:

${ n = \frac{2}{3} \times 5.03 \times 10^{-4} \, \text{mol} }$

Simplifying, we get:

${ n = 3.35 \times 10^{-4} \, \text{mol} }$

Now, we can calculate the volume of ammonia that should be formed using the ideal gas law:

${ V = \frac{nRT}{P} }$

Substituting the values, we get:

${ V = \frac{(3.35 \times 10^{-4} \, \text{mol})(0.0821 \, \text{L atm/mol K})(298 \, \text{K})}{(1 \, \text{atm})} }$

Simplifying, we get:

${ V = 8.23 \times 10^{-3} \, \text{L} }$

Converting this to cm³, we get:

${ V = 8.23 \, \text{cm}^3 }$

Actual Yield

We are given that 2 cm³ of ammonia was actually formed. This is the actual yield.

Percentage Yield

To calculate the percentage yield, we can use the following formula:

${ \text{Percentage Yield} = \frac{\text{Actual Yield}}{\text{Theoretical Yield}} \times 100\% }$

Substituting the values, we get:

${ \text{Percentage Yield} = \frac{2 \, \text{cm}^3}{8.23 \, \text{cm}^3} \times 100\% }$

Simplifying, we get:

${ \text{Percentage Yield} = 24.3\% }$

Therefore, the percentage yield of ammonia is 24.3%.

Conclusion

In this problem, we calculated the percentage yield of ammonia formed by the reaction between nitrogen and hydrogen. We found that the percentage yield is 24.3%. This means that only 24.3% of the theoretical yield of ammonia was actually formed.

This problem demonstrates the importance of calculating the percentage yield in chemical reactions. It helps us to understand the efficiency of the reaction and to identify any potential problems or limitations.

Discussion

This problem can be used to discuss the following topics:

• The concept of limiting reagents and how to identify them.
• The importance of calculating the percentage yield in chemical reactions.
• The factors that affect the percentage yield, such as temperature, pressure, and concentration.
• The relationship between the actual yield and the theoretical yield.
• The significance of the percentage yield in real-world applications, such as industrial processes and environmental monitoring.

Additional Questions

1. What is the effect of increasing the temperature on the percentage yield of ammonia?
2. How does the pressure of the reaction affect the percentage yield of ammonia?
3. What is the effect of increasing the concentration of hydrogen on the percentage yield of ammonia?
4. How does the presence of impurities in the reaction affect the percentage yield of ammonia?
5. What is the significance of the percentage yield in the context of environmental monitoring and industrial processes?
   Q&A: Nitrogen and Hydrogen React to Form Ammonia =====================================================

Q: What is the balanced chemical equation for the reaction between nitrogen and hydrogen to form ammonia?

A: The balanced chemical equation for the reaction between nitrogen and hydrogen to form ammonia is:

${ N_2(g) + 3 H_2(g) \Rightarrow 2 NH_3(g) }$

Q: What is the concept of limiting reagents, and how is it used in this problem?

A: The concept of limiting reagents refers to the idea that in a chemical reaction, one reactant is present in a smaller amount than the other reactants, and this limiting reactant determines the amount of product that can be formed. In this problem, hydrogen is the limiting reagent, and nitrogen is in excess.

Q: How is the number of moles of ammonia that should be formed calculated?

A: The number of moles of ammonia that should be formed is calculated using the balanced chemical equation and the number of moles of hydrogen that reacted. The balanced chemical equation tells us that 3 moles of hydrogen react with 1 mole of nitrogen to form 2 moles of ammonia. We can use this information to calculate the number of moles of ammonia that should be formed.

Q: What is the significance of the percentage yield in chemical reactions?

A: The percentage yield is a measure of the efficiency of a chemical reaction. It is the ratio of the actual yield of a product to the theoretical yield of the product, expressed as a percentage. The percentage yield is important because it helps us to understand the efficiency of a reaction and to identify any potential problems or limitations.

Q: What are some factors that can affect the percentage yield of a chemical reaction?

A: Some factors that can affect the percentage yield of a chemical reaction include:

• Temperature: Increasing the temperature can increase the rate of reaction, but it can also lead to the formation of byproducts or the degradation of the product.
• Pressure: Increasing the pressure can increase the rate of reaction, but it can also lead to the formation of byproducts or the degradation of the product.
• Concentration: Increasing the concentration of the reactants can increase the rate of reaction, but it can also lead to the formation of byproducts or the degradation of the product.
• Impurities: The presence of impurities in the reaction can affect the percentage yield by reacting with the reactants or products.

Q: What is the relationship between the actual yield and the theoretical yield of a chemical reaction?

A: The actual yield is the amount of product that is actually formed in a chemical reaction, while the theoretical yield is the amount of product that should be formed based on the balanced chemical equation. The percentage yield is the ratio of the actual yield to the theoretical yield, expressed as a percentage.

Q: What is the significance of the percentage yield in real-world applications?

A: The percentage yield is important in real-world applications because it helps us to understand the efficiency of a chemical reaction and to identify any potential problems or limitations. It is used in a variety of fields, including industrial processes, environmental monitoring, and pharmaceutical manufacturing.

Q: How can the percentage yield be improved in a chemical reaction?

A: The percentage yield can be improved in a chemical reaction by:

• Increasing the temperature or pressure to increase the rate of reaction.
• Increasing the concentration of the reactants to increase the rate of reaction.
• Removing impurities from the reaction to prevent them from reacting with the reactants or products.
• Using catalysts to increase the rate of reaction and reduce the formation of byproducts.

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

A: Some common mistakes that can affect the percentage yield of a chemical reaction include:

• Not using the correct amount of reactants.
• Not using the correct temperature or pressure.
• Not removing impurities from the reaction.
• Not using catalysts to increase the rate of reaction and reduce the formation of byproducts.

Q: How can the percentage yield be calculated in a chemical reaction?

A: The percentage yield can be calculated in a chemical reaction by using the following formula:

${ \text{Percentage Yield} = \frac{\text{Actual Yield}}{\text{Theoretical Yield}} \times 100\% }$

This formula can be used to calculate the percentage yield of a product in a chemical reaction.