Problem 2 - Chemistry and Chemical Reactivity

Question

Write a balanced chemical equation for the production of ammonia, \(\mathrm{NH}_{3}(\mathrm{g}),\) from \(\mathrm{N}_{2}(\mathrm{g})\) and \(\mathrm{H}_{2}(\mathrm{g})\)

Step-by-Step Solution

Answer

The balanced chemical equation is: \(\mathrm{N}_2(\mathrm{g}) + 3\mathrm{H}_2(\mathrm{g}) \rightarrow 2\mathrm{NH}_3(\mathrm{g})\).

Step 1: Write the Unbalanced Equation

First, we identify the reactants and products of the reaction. The reactants are nitrogen gas \(\mathrm{N}_2(\mathrm{g})\), and hydrogen gas \(\mathrm{H}_2(\mathrm{g})\), and the product is ammonia \(\mathrm{NH}_3(\mathrm{g})\). So, the unbalanced equation is: \[\mathrm{N}_2(\mathrm{g}) + \mathrm{H}_2(\mathrm{g}) \rightarrow \mathrm{NH}_3(\mathrm{g})\]

Step 2: Balance Nitrogen Atoms

We start by balancing the nitrogen atoms. There are 2 nitrogen atoms in \(\mathrm{N}_2\) and only 1 in \(\mathrm{NH}_3\). To balance, we need 2 ammonia molecules. Update the equation: \[\mathrm{N}_2(\mathrm{g}) + \mathrm{H}_2(\mathrm{g}) \rightarrow 2\mathrm{NH}_3(\mathrm{g})\]

Step 3: Balance Hydrogen Atoms

Next, we balance the hydrogen atoms. Each ammonia molecule has 3 hydrogen atoms, for a total of 6 in \(2\mathrm{NH}_3\). We need 3 \(\mathrm{H}_2\) molecules to provide 6 hydrogen atoms. Update the equation: \[\mathrm{N}_2(\mathrm{g}) + 3\mathrm{H}_2(\mathrm{g}) \rightarrow 2\mathrm{NH}_3(\mathrm{g})\]

Step 4: Verify the Balancing

Verify that there are equal numbers of each type of atom on both sides of the equation. The equation should have 2 nitrogen atoms and 6 hydrogen atoms on both sides, confirming that it is balanced.

Key Concepts

Ammonia Production

Ammonia production is a critical chemical process in industrial applications. It primarily involves the Haber-Bosch process, which is widely used to synthesize ammonia (\(\text{NH}_{3}\)) from nitrogen (\(\text{N}_{2}\)) and hydrogen gases (\(\text{H}_{2}\)). This reaction takes place under specific conditions involving high temperatures and pressures, usually in the presence of an iron catalyst.

Producing ammonia is essential due to its application in fertilizers, which helps meet the agricultural demands of growing populations. Additionally, ammonia serves as a starting material for many other chemical products, making it a cornerstone of the chemical industry.

Chemical Reactions

Chemical reactions involve the transformation of reactants into products via the breaking and forming of chemical bonds. In the production of ammonia, the chemical reaction involves combining nitrogen and hydrogen gases to produce ammonia gas.

Representing this process in a chemical equation requires identifying the reactants and products correctly. In this context:

• Reactants: \(\text{N}_2(\text{g})\) and \(\text{H}_2(\text{g})\) are the starting gases.
• Product: \(\text{NH}_3(\text{g})\) is the ammonia gas formed.

The balanced equation ensures that the number of each type of atom is conserved, following the Law of Conservation of Mass, which states that atoms are neither created nor destroyed in a chemical reaction.

Stoichiometry

Stoichiometry is a critical concept in chemistry that deals with the quantitative relationships between reactants and products in a chemical reaction. When balancing chemical equations, stoichiometry ensures that we have the correct amounts of reactants to fully react without any leftovers, and the correct amounts of products that are formed.

In the context of ammonia production, balancing the chemical equation demonstrates stoichiometry. To do this, we equate the number of nitrogen and hydrogen atoms on both sides of the reaction:

• 2 nitrogen atoms from \( \text{N}_2 \) on the reactant side pair with 2 \( \text{NH}_3 \) to give 2 nitrogen atoms on the product side.
• 6 hydrogen atoms from 3 \( \text{H}_2 \) molecules align with the 6 hydrogen atoms in 2 \( \text{NH}_3 \) molecules.

This balanced equation \(\text{N}_2(\text{g}) + 3\text{H}_2(\text{g}) \rightarrow 2\text{NH}_3(\text{g})\) not only reflects the stoichiometric relationships but also supports the efficiency of the chemical reaction to ensure the maximum use of reactants.