The following pictures represent the initial and equilibrium states for the exothermic decomposition of gaseous A mol- ecules (red) to give gaseous B molecules (blue). (a) Write a balanced chemical equation for the reaction.

Verified step by step guidance

1. Identify the reactants and products from the description: A molecules (red) decompose to form B molecules (blue).
2. Write the unbalanced chemical equation: A (g) -> B (g).
3. Count the number of A molecules in the initial state and the number of B molecules in the equilibrium state.
4. Use the stoichiometry from the initial and equilibrium states to balance the chemical equation.
5. Ensure the equation is balanced by checking that the number of atoms of each element is the same on both sides of the equation.

Key Concepts

Balanced Chemical Equation

A balanced chemical equation represents a chemical reaction with equal numbers of each type of atom on both sides of the equation. This ensures the law of conservation of mass is upheld, meaning that matter is neither created nor destroyed during the reaction. Balancing involves adjusting coefficients in front of the chemical formulas to achieve this equality.

Exothermic Reaction

An exothermic reaction is a type of chemical reaction that releases energy, usually in the form of heat, to its surroundings. This occurs when the total energy of the products is lower than that of the reactants, resulting in a net release of energy. Understanding this concept is crucial for predicting temperature changes and the direction of the reaction.

Equilibrium State

The equilibrium state in a chemical reaction refers to the point at which the rates of the forward and reverse reactions are equal, leading to constant concentrations of reactants and products over time. In the context of the decomposition of gaseous A to B, recognizing the equilibrium helps in understanding how the system behaves under different conditions, such as changes in temperature or pressure.