Chapter 1 – Chemical Equilibrium

Vocabulary flashcards covering the key terms, laws, rate equations, and equilibrium constant definitions from Chapter 1 – Chemical Equilibrium.

Chemical Equilibrium

The state of a reversible reaction in which the rate of the forward reaction becomes equal to the rate of the backward reaction, and the concentrations of reactants and products remain constant.

Law of Mass Action

The principle stating that the rate of a chemical reaction is directly proportional to the product of the active masses of reactants, each raised to the power of its coefficient in the balanced chemical equation.

Reversible Reaction

A reaction that takes place in both forward and backward directions, represented by examples such as $N_2 + 3H_2 \rightleftharpoons 2NH_3$.

Irreversible Reaction

A reaction that takes place only in one direction, represented by examples such as $C + O_2 \rightarrow CO_2$.

Forward Reaction

The reaction in which reactants combine to form products, represented generally as $A + B \rightarrow C + D$.

Backward Reaction

The reaction in which products react to form the original reactants, represented generally as $C + D \rightarrow A + B$.

Equilibrium Constant ($K_c$)

The ratio of product concentrations to reactant concentrations at equilibrium, each raised to its stoichiometric coefficient, given by $K_c = \frac{k_f}{k_b} = \frac{[C]^c[D]^d}{[A]^a[B]^b}$.

Forward Rate ($R_f$)

The rate of the forward reaction given by the formula $R_f = k_f[A][B]$.

Backward Rate ($R_b$)

The rate of the backward reaction given by the formula $R_b = k_b[C][D]$.

Equilibrium Condition

The point in a reversible reaction where the rate of the forward reaction equals the rate of the backward reaction, defined as $R_f = R_b$.

Coefficient Difference ($\Delta n$)

The value defined as the sum of product coefficients minus the sum of reactant coefficients in a balanced chemical equation.

Unit of $K_c$

The concentration unit expressed as $(mol\,dm^{-3})^{\Delta n}$, which results in no unit when $\Delta n = 0$.