equilibrium hem regents

Collision Theory

The theory stating that for a chemical reaction to occur, reactant particles must collide with sufficient energy and proper orientation.

Effective Collision

A collision that leads to a chemical reaction, requiring sufficient energy and the correct orientation of particles.

Factors Influencing Reaction Rates

The five factors are temperature, concentration, surface area, catalysts, and pressure (for gases). They influence reaction rates by affecting the frequency and energy of collisions.

Potential Energy (PE) Diagrams

Graphs that depict the energy changes during a chemical reaction, showing the energy of reactants, products, and the activation energy required for the reaction.

Endothermic Reaction

A reaction that absorbs energy, resulting in products that have higher potential energy than the reactants.

Exothermic Reaction

A reaction that releases energy, resulting in products that have lower potential energy than the reactants.

Entropy

A measure of disorder or randomness in a system, where an increase indicates a greater distribution of energy.

Changes that Increase Entropy

Increase in temperature, increase in volume, phase changes from solid to liquid or gas, mixing of different substances, and increasing the number of moles.

Gibbs Free Energy (ΔG)

A thermodynamic quantity used to predict whether a process will occur spontaneously; calculated using ΔG = ΔH - TΔS.

Spontaneous Reaction

A reaction that occurs without external influence; it can be always spontaneous, never spontaneous, or spontaneous only at certain temperatures.

Dynamic Equilibrium Conditions

The four conditions are: closed system, constant temperature, constant pressure, and the rates of the forward and reverse reactions are equal.

Le Chatelier's Principle

A principle stating that if a dynamic equilibrium is disturbed, the system will adjust to counteract the disturbance and re-establish equilibrium.

Increasing Concentration Effect

Shifts the equilibrium towards the side that consumes the added reactants or products.

Decreasing Temperature Effect

Shifts the equilibrium towards the exothermic direction to increase heat.

Increasing Pressure Effect

Shifts the equilibrium towards the side with fewer moles of gas.