Ammonia reacts slowly in air to produce nitrogen monoxide and water vapor:
NH₃(g) + O₂(g) ⇌ NO(g) + H₂O(g) + Heat
b. Write the equilibrium equation.

Verified step by step guidance

1. Step 1: Begin by writing the balanced chemical equation for the reaction. The given reaction is NH₃(g) + O₂(g) ⇌ NO(g) + H₂O(g) + Heat. To balance it, ensure that the number of atoms of each element is the same on both sides of the equation.
2. Step 2: Balance the nitrogen (N) atoms. There is 1 nitrogen atom in NH₃ on the reactant side and 1 nitrogen atom in NO on the product side. This is already balanced.
3. Step 3: Balance the hydrogen (H) atoms. There are 3 hydrogen atoms in NH₃ on the reactant side. On the product side, H₂O contains 2 hydrogen atoms. To balance, place a coefficient of 2 in front of NH₃ and a coefficient of 3 in front of H₂O.
4. Step 4: Balance the oxygen (O) atoms. On the reactant side, O₂ contains 2 oxygen atoms. On the product side, NO and H₂O contribute oxygen atoms. Adjust the coefficients to balance the oxygen atoms.
5. Step 5: Verify that all elements are balanced and write the final equilibrium equation. Ensure that the reaction is reversible (indicated by the ⇌ symbol) and includes the heat term to indicate that it is exothermic.

Key Concepts

Chemical Equilibrium

Chemical equilibrium occurs when the rates of the forward and reverse reactions are equal, resulting in constant concentrations of reactants and products. In the context of the given reaction, this means that ammonia (NH3) and oxygen (O2) are converting to nitrogen monoxide (NO) and water vapor (H2O) at a rate that balances with the reverse process, allowing the system to maintain a stable state.

Equilibrium Constant (K)

The equilibrium constant (K) is a numerical value that expresses the ratio of the concentrations of products to reactants at equilibrium, each raised to the power of their coefficients in the balanced equation. For the reaction provided, K can be calculated using the concentrations of NO and H2O divided by those of NH3 and O2, reflecting the extent to which the reaction favors products or reactants.

Le Chatelier's Principle

Le Chatelier's Principle states that if a dynamic equilibrium is disturbed by changing the conditions, the system will adjust to counteract the change and restore a new equilibrium. This principle is crucial for understanding how changes in concentration, temperature, or pressure can affect the position of the equilibrium in the reaction between ammonia and oxygen.