"The equilibrium constant of a chemical reaction is the value of its reaction quotient at chemical equilibrium, a state approached by a dynamic chemical system after sufficient time has elapsed at which its composition has no measurable tendency towards further change."
The ratio of concentrations of products to reactants at any point in reaction, which helps determine whether the reaction has reached equilibrium or not.
Chemical Equilibrium: The state of a reaction where the rate of the forward reaction is equal to the rate of the reverse reaction, resulting in a constant concentration of reactants and products.
Equilibrium Constant (Kc/Kp): A mathematical representation of the concentration of products and reactants at equilibrium. Kc is used for concentration and Kp for partial pressures.
Reaction Quotient (Qc/Qp): A mathematical representation of the concentration of products and reactants at any time during a reaction, which can be compared to the equilibrium constant to determine if a reaction is at equilibrium.
Calculating Qc/Qp: The process of determining the numerical value of Qc/Qp based on the concentration of reactants and products.
Le Chatelier’s Principle: A principle that states that when a system at equilibrium is subjected to a stress, the equilibrium position will shift in the direction that counteracts the stress.
Effect of Temperature on Equilibrium: Temperature affects the equilibrium constant, and the reaction quotient. An increase in temperature favours the endothermic direction of the reaction, whereas a decrease in temperature favours the exothermic direction.
Effect of Pressure on Equilibrium: Pressure affects equilibrium for gaseous reactants and products. An increase in pressure of the system tends to shift the equilibrium towards the side with fewer moles of gas.
Effect of Concentration on Equilibrium: Concentration affects the reaction quotient of a system. Increasing the concentration of reactants will shift the equilibrium towards the side of products while increasing the concentration of products will shift the equilibrium towards reactants.
Equilibrium Shift: The impact of a stress or change on the direction of the reaction equilibrium position.
Stanchematry table: A table which lists the concentration of each species that is present in a solution at any point in time.
Equilibrium Expression: The mathematical relationship between the concentrations of the reactants and products in a reaction.
Equilibrium Constant Expression: The expression of the mathematical equation for determining the equilibrium constant.
Acid-Base Equilibria: A type of equilibrium that involves the transfer of protons (H+) between acids and bases.
Solubility Product: The product of the concentration of the ions in a solution, typically for ionic compounds with low solubility.
Non-Ideal Solutions: When the concentration of solutes in a solution affects the behaviour of the solvents, resulting in non-ideal behaviour.
Effect of Catalysts on Equilibrium: Catalysts increase the rate of a reaction without affecting the equilibrium constant, thus contributing towards the attainment of equilibrium.
Equilibrium Constant and Free Energy: The relationship between the equilibrium constant and Gibbs Free Energy of the reaction.
Equilibrium of Multiple Reactions: When multiple reactions are going on at the same time, the concept of equilibrium shifts to the most stable species among these reactions.
Equilibrium constant and pH: How the value of the concentration of hydrogen ions in a solution affects the calculation and comparison between the equilibrium constant and the reaction quotient.
Electrochemical Equilibria: A type of equilibrium that deals with the transfer of electrons between reactants and products, including redox reactions.
Qc: This is the reaction quotient expressed in terms of concentrations of reactants and products. It is used to determine whether a reaction is at equilibrium by comparing its value to the equilibrium constant (Kc). If Qc is equal to Kc, the reaction is at equilibrium. If Qc is greater than Kc, the reaction will shift in the reverse direction to reach equilibrium. If Qc is less than Kc, the reaction will shift in the forward direction to reach equilibrium.
Qp: This is the reaction quotient expressed in terms of partial pressures of reactants and products. It is used for reactions that involve gases. It follows the same principles as Qc.
Qx: This is the general reaction quotient and can be expressed in any appropriate units, depending on the situation. For example, if the reaction involves solids or liquids, Qx can be expressed in terms of their mole fractions.
Qsp: This is the solubility product constant, which is used for ionic compounds that dissolve in water. Qsp is calculated by multiplying the concentrations of the ions produced in the solution at equilibrium. If Qsp is greater than the solubility product (Ksp), a precipitate will form. If Qsp is less than Ksp, the solution is unsaturated and more solid can dissolve.
Qf/Qb: These are the reaction quotients for the forward and backward reactions, respectively. They are used for reversible reactions to determine which direction the reaction will shift to reach equilibrium.
Qw: This is the reaction quotient for water in acid-base reactions. It is used to determine the concentration of the hydronium ion (H3O+) or hydroxide ion (OH-) at equilibrium.
QK: This is the reaction quotient for the equilibrium constant, K. It is used to calculate the reaction quotient at any point during the reaction and to compare it to the equilibrium constant. If QK is greater than K, the reaction will shift in the reverse direction to reach equilibrium. If QK is less than K, the reaction will shift in the forward direction to reach equilibrium.
"a state approached by a dynamic chemical system after sufficient time has elapsed at which its composition has no measurable tendency towards further change."
"For a given set of reaction conditions, the equilibrium constant is independent of the initial analytical concentrations of the reactant and product species in the mixture."
"Thus, given the initial composition of a system, known equilibrium constant values can be used to determine the composition of the system at equilibrium."
"reaction parameters like temperature, solvent, and ionic strength may all influence the value of the equilibrium constant."
"A knowledge of equilibrium constants is essential for the understanding of many chemical systems."
"biochemical processes such as oxygen transport by hemoglobin in blood and acid–base homeostasis in the human body."
"Stability constants, formation constants, binding constants, association constants and dissociation constants are all types of equilibrium constants."
"temperature... may all influence the value of the equilibrium constant."
"solvent... may all influence the value of the equilibrium constant."
"acid–base homeostasis in the human body."
"oxygen transport by hemoglobin in blood."
"its composition has no measurable tendency towards further change."
"For a given set of reaction conditions, the equilibrium constant is independent of the initial analytical concentrations of the reactant and product species in the mixture."
"Stability constants, formation constants, binding constants, association constants and dissociation constants are all types of equilibrium constants."
"determine the composition of the system at equilibrium."
"The equilibrium constant is independent of the initial analytical concentrations of the reactant and product species in the mixture."
"a state approached by a dynamic chemical system after sufficient time has elapsed"
"The equilibrium constant is independent of the initial analytical concentrations of the reactant and product species in the mixture."
"Stability constants, formation constants, binding constants, association constants, and dissociation constants are all types of equilibrium constants."