The Stoichiometric Relationship

Oct 13, 2025 by wbrum.org 55 views

The Unbalanced Equation

Consider the following unbalanced equation:

${ NH_3(g) \rightarrow N_2(g) + H_2(g) }$

This equation represents the decomposition of ammonia (NH3) into nitrogen gas (N2) and hydrogen gas (H2). However, the equation is unbalanced, meaning that the number of atoms of each element on the reactant side does not equal the number of atoms on the product side.

Balancing the Equation

To balance the equation, we need to add coefficients in front of the formulas of the reactants or products to ensure that the number of atoms of each element is the same on both sides. The balanced equation is:

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

Understanding the Problem

The problem asks us to find the number of moles of N2 produced by the decomposition of 3.20 moles of ammonia. To solve this problem, we need to use the concept of stoichiometry, which is the study of the quantitative relationships between reactants and products in chemical reactions.

The Stoichiometric Relationship

From the balanced equation, we can see that 2 moles of NH3 produce 1 mole of N2. This is a stoichiometric relationship, which can be expressed as a mole ratio:

${ \frac{1 \text{ mole of } N_2}{2 \text{ moles of } NH_3} }$

Calculating the Number of Moles of N2

To find the number of moles of N2 produced by the decomposition of 3.20 moles of ammonia, we can use the mole ratio from the balanced equation. We can set up a proportion:

${ \frac{1 \text{ mole of } N_2}{2 \text{ moles of } NH_3} = \frac{x \text{ moles of } N_2}{3.20 \text{ moles of } NH_3} }$

Where x is the number of moles of N2 we want to find.

Solving the Proportion

To solve the proportion, we can cross-multiply:

${ 1 \times 3.20 = 2 \times x }$

${ 3.20 = 2x }$

Dividing both sides by 2, we get:

${ x = \frac{3.20}{2} }$

${ x = 1.60 }$

Therefore, the number of moles of N2 produced by the decomposition of 3.20 moles of ammonia is 1.60 moles.

Conclusion

In conclusion, to find the number of moles of N2 produced by the decomposition of 3.20 moles of ammonia, we need to use the concept of stoichiometry and the balanced equation. We can set up a proportion using the mole ratio from the balanced equation and solve for the number of moles of N2. The result is 1.60 moles of N2.

Additional Information

To find the number of moles of N2 produced by the decomposition of any amount of ammonia, we can use the following formula:

${ \text{moles of } N_2 = \frac{\text{moles of } NH_3}{2} }$

Where moles of NH3 is the number of moles of ammonia decomposed.

Example Problems

If 4.80 moles of ammonia are decomposed, how many moles of N2 will be produced?
If 2.40 moles of ammonia are decomposed, how many moles of H2 will be produced?

Answer Key

2.40 moles of N2
3.60 moles of H2
Q&A: Understanding the Decomposition of Ammonia =====================================================

Frequently Asked Questions

Q: What is the balanced equation for the decomposition of ammonia?

A: The balanced equation for the decomposition of ammonia is:

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

Q: How many moles of N2 are produced by the decomposition of 1 mole of ammonia?

A: According to the balanced equation, 2 moles of NH3 produce 1 mole of N2. Therefore, 1 mole of NH3 will produce 0.5 moles of N2.

Q: How many moles of H2 are produced by the decomposition of 1 mole of ammonia?

A: According to the balanced equation, 2 moles of NH3 produce 3 moles of H2. Therefore, 1 mole of NH3 will produce 1.5 moles of H2.

Q: What is the mole ratio of NH3 to N2 in the balanced equation?

A: The mole ratio of NH3 to N2 in the balanced equation is 2:1. This means that 2 moles of NH3 produce 1 mole of N2.

Q: What is the mole ratio of NH3 to H2 in the balanced equation?

A: The mole ratio of NH3 to H2 in the balanced equation is 2:3. This means that 2 moles of NH3 produce 3 moles of H2.

Q: How many moles of ammonia are required to produce 1 mole of N2?

A: According to the balanced equation, 2 moles of NH3 produce 1 mole of N2. Therefore, 2 moles of ammonia are required to produce 1 mole of N2.

Q: How many moles of ammonia are required to produce 1 mole of H2?

A: According to the balanced equation, 2 moles of NH3 produce 3 moles of H2. Therefore, 2/3 moles of ammonia are required to produce 1 mole of H2.

Q: What is the limiting reactant in the decomposition of ammonia?

A: The limiting reactant in the decomposition of ammonia is the reactant that is consumed first. In this case, the limiting reactant is NH3.

Q: How can we determine the limiting reactant in a chemical reaction?

A: We can determine the limiting reactant in a chemical reaction by comparing the mole ratio of the reactants to the mole ratio of the products. The reactant that is consumed first is the limiting reactant.

Q: What is the yield of N2 in the decomposition of ammonia?

A: The yield of N2 in the decomposition of ammonia is 100% because the balanced equation shows that 2 moles of NH3 produce 1 mole of N2.

Q: What is the yield of H2 in the decomposition of ammonia?

A: The yield of H2 in the decomposition of ammonia is 100% because the balanced equation shows that 2 moles of NH3 produce 3 moles of H2.

Q: How can we increase the yield of N2 in the decomposition of ammonia?

A: We can increase the yield of N2 in the decomposition of ammonia by increasing the amount of NH3 that is decomposed.

Q: How can we increase the yield of H2 in the decomposition of ammonia?

A: We can increase the yield of H2 in the decomposition of ammonia by increasing the amount of NH3 that is decomposed.

Q: What are some common applications of the decomposition of ammonia?

A: Some common applications of the decomposition of ammonia include the production of nitrogen gas and hydrogen gas, which are used in various industrial processes.

Q: What are some common hazards associated with the decomposition of ammonia?

A: Some common hazards associated with the decomposition of ammonia include the release of toxic gases, such as nitrogen dioxide and hydrogen chloride, and the risk of explosion.

Q: How can we safely handle the decomposition of ammonia?

A: We can safely handle the decomposition of ammonia by following proper safety protocols, such as wearing protective gear and working in a well-ventilated area.

Q: What are some common sources of ammonia?

A: Some common sources of ammonia include fertilizers, cleaning products, and industrial processes.

Q: What are some common uses of ammonia?

A: Some common uses of ammonia include the production of fertilizers, the cleaning of surfaces, and the production of plastics and other synthetic materials.

Q: What are some common environmental concerns associated with the decomposition of ammonia?

A: Some common environmental concerns associated with the decomposition of ammonia include the release of toxic gases, such as nitrogen dioxide and hydrogen chloride, and the risk of water pollution.

Q: How can we minimize the environmental impact of the decomposition of ammonia?

A: We can minimize the environmental impact of the decomposition of ammonia by following proper safety protocols, such as wearing protective gear and working in a well-ventilated area, and by using environmentally friendly methods of decomposition.