Equilibrium in Chemistry and Physical Processes

A reaction where all reactants and products are in the same physical state (gas, liquid, or solid)

A reaction where reactants and products exist in different physical states.

A principle stating that a system at equilibrium will shift to relieve stress caused by changes in conditions.

Adding a reactant or product to an equilibrium system will cause the reaction to shift in a direction that consumes the added substance.

Removing a reactant or product from an equilibrium system will cause the reaction to shift in a direction that produces that substance.

Increasing temperature favors the endothermic reaction; decreasing temperature favors the exothermic reaction.

The equilibrium constant (K) changes with temperature.

The reaction quotient (Q) measures the relative amounts of reactants and products at a given moment.

A constant that represents the ratio of products to reactants at equilibrium, where each concentration is raised to the power of its stoichiometric coefficient.

The equilibrium constant is independent of the initial concentrations of reactants and products. It only depends on the temperature.

If the equilibrium constant (Kc) is greater than 10^3, the reaction strongly favors the formation of products at equilibrium.

If the equilibrium constant (Kc) is less than 10^-3, the reaction strongly favors the formation of reactants at equilibrium.

When Qc < Kc: the reaction proceeds forward, favoring the formation of products. When Qc > Kc: the reaction proceeds in the reverse direction, favoring the formation of reactants. When Qc = Kc: the reaction is at equilibrium.

A series of steps involved in solving equilibrium problems where you know initial concentrations but not equilibrium concentrations. This involves writing the balanced equation, creating an ICE (Initial, Change, Equilibrium) table, and using Kc to solve for equilibrium concentrations.

Adding a catalyst to a reaction does not change the equilibrium constant (Kc). It only speeds up the rate at which equilibrium is reached.

Substances that dissolve in water to produce ions, allowing them to conduct electricity.

Electrolytes that dissociate completely into ions when dissolved in water.

Electrolytes that only partially dissociate into ions when dissolved in water.

A theory that defines acids as substances that donate hydrogen ions (H+) and bases as substances that accept hydrogen ions (H+).

A theory that defines acids as substances that accept electron pairs and bases as substances that donate electron pairs.

A state of balance where the rate of the forward reaction equals the rate of the reverse reaction.

A chemical equation that represents the equilibrium between ions and undissociated molecules in a weak electrolyte.

The effect of pressure change on a reaction at equilibrium depends on the change in the total number of moles of gaseous products. If the number of moles of gaseous products increases, the equilibrium shifts to the left, and vice versa.

Pressure changes don't significantly affect the equilibrium of reactions involving only solids or liquids because their volumes are relatively constant.

Decreasing the volume of a reaction vessel is equivalent to increasing the pressure, and vice versa. This shift in equilibrium favors the side with fewer moles of gas.

A catalyst speeds up a chemical reaction by providing an alternative pathway with lower activation energy, but it doesn't affect the equilibrium position. It speeds up both forward and reverse reactions equally.

Adding an inert gas (like argon) to a reaction system at constant volume doesn't change the equilibrium position. This is because the partial pressures of the reactants and products remain constant.

Electrolytes are substances that conduct electricity when dissolved in water because they dissociate into ions. Non-electrolytes don't conduct electricity because they don't produce ions in solution.

Solutions that resist changes in pH when diluted or when small amounts of acid or alkali are added.

The pH of a salt solution depends on the strength of the acid and base that formed it.

A solution containing a weak acid and its conjugate base.

A solution containing a weak base and its conjugate acid.

The ability of a substance to dissolve in a solvent.

The degree to which an acid ionizes in solution; a measure of acid strength. Higher Ka values indicate stronger acids.

The equilibrium constant for the ionization of a weak base; a measure of base strength. Higher Kb values indicate stronger bases.

The negative logarithm of the acid dissociation constant (Ka). A lower pKa value indicates a stronger acid.

The negative logarithm of the base ionization constant (Kb). A lower pKb value indicates a stronger base.

The extent to which an acid or base ionizes in solution. A measure of the fraction of molecules that break down into ions.

The initial concentration of an undissociated acid or base before ionization occurs.

A way to represent the equilibrium constant for the ionization of a weak acid or base using initial concentration and degree of ionization. It simplifies calculations for these systems.