Equilibrium Flashcards
Closed System
Chemical system that is separated from its surrounding by a definite boundary so that matter can neither enter nor leave the system (energy is free to enter and leave). Ex: sealed pop can.
Equilibrium
State of a closed system with constant macroscopic properties (no observable change is taking place).
Solubility Equilibrium
Constant state of a system in which excess solute is in contact with the saturated solution; the rate of dissolving equals the rate of crystallizing.
Chemical Reaction Equilibrium
An apparently static state of a reaction system where the reactants and products may be favoured but the rates of the forward and reverse reactions are equal.
Dynamic Equilibrium
The concept of balance between two opposing processes (forward and reverse) that occur at the same rate.
Forward Reaction
The left-to-right change in a written chemical equilibrium equation.
Reverse Reaction
Usually in reference to the right-to-left change in an equilibrium equation.
Equilibrium Constant Kc
A constant value for a reaction system over a range of concentrations.
Equilibrium Law
Mathematical expression which relates concentrations of reactants and products to the equilibrium constant; Kc = [C]c[D]d/([A]a[B]b). A, B, C, and D represent chemical entity formulas and a, b, c, and d represent their coefficients in the balanced chemical equation.
LeChatelier’s Principle
The statement: when a chemical system at equilibrium is disturbed by a change in a property of the system, the system always appears to react in the direction that opposes the change, until a new equilibrium is reached.
Equilibrium Shift
Change in concentrations that occurs when a system at equilibrium is disrupted (e.g. by the addition of more reactant).
Phase Equilibrium
Type of equilibrium involving a single chemical substance existing in more than one phase (state) in a closed system.
