CHEM 17

Free energy

The energy available to do work, calculated as the difference between the change in enthalpy and the product of the entropy change and the absolute temperature.

Ammonia

A valuable nitrogen source essential for plant growth.

Reversible reaction

A chemical reaction that can proceed in both the forward and reverse directions.

Equilibrium

A state where opposing processes are in balance.

Chemical equilibrium

State where the forward and reverse reactions occur at equal rates, balancing each other.

Force

A push or pull on an object.

Sublimation

The process where molecules change directly from the solid phase to the gas phase.

Cato Maximilian Guldberg and Peter Waage

proposed and developed the law of chemical equilibrium

Law of chemical equilibrium

States that at a given temperature, a chemical system reaches a constant ratio of reactant and product concentrations.

Equilibrium constant

(K_eq) Ratio of product concentrations to reactant concentrations, raised to the power of their coefficients in the balanced equation.

Homogeneous equilibrium

Equilibrium where all reactants and products are in the same physical state.

Heterogeneous equilibrium

Equilibrium where reactants and products are present in more than one physical state.

Equilibrium concentrations

Concentrations of substances in a system at equilibrium, determined experimentally.

Equilibrium constant expression

Ratio of molar concentrations of products to reactants.

Henri-Louis Le Châtelier

Discovered that there are ways to control equilibria to make reactions more productive.

Le Châtelier's Principle

If a stress is applied to a system at equilibrium, the system shifts to relieve the stress.

Stress

Any change in a system at equilibrium that disrupts the equilibrium.

Desiccant

A substance that absorbs water.

Solubility product constant

Equilibrium constant expression for the dissolving of sparingly soluble compounds (K_sp).

Common ion

An ion present in multiple ionic compounds.

Common ion effect

The decrease in solubility due to the presence of a common ion.

chemical equilibrium

Described by an equilibrium constant expression that relates the concentrations of reactants and products