Spontaneity and Reaction Rates

A series of vocabulary flashcards covering key concepts related to spontaneity, reaction rates, and catalysis.

Spontaneous Reaction

A reaction that favors the formation of products and is thermodynamically favorable.

Activation Energy (Ea)

The minimum energy required for reactant particles to start a chemical reaction.

Collision Theory

Reactions occur when particles collide with sufficient energy and proper orientation.

Kinetic Molecular Theory

Theory stating that particles are constantly in motion, with energy proportional to temperature.

Activation Energy and Reaction Rate

Fast reactions have low activation energy, while slow reactions have high activation energy.

Concentration's Effect on Reaction Rate

Higher concentration increases the number of particles, leading to more collisions and faster reactions.

Temperature's Effect on Reaction Rate

Higher temperature increases the kinetic energy of particles and the fraction that can react.

Rate Law of a Reaction

Mathematical expression of the reaction rate as a function of reactant concentrations.

Rate-Determining Step

The slowest step in a reaction mechanism that dictates the overall reaction rate.

Order of Reaction

Describes how many molecules of a reactant participate in the rate-determining step.

Zero Order Reaction

A reaction where the rate is independent of the concentration of a reactant.

Gibbs Free Energy (ΔG)

Thermodynamic potential used to predict the feasibility of a reaction.

Intermediates

High-energy, unstable entities formed and consumed during a reaction.

Transition States

High-energy, unstable states at the midpoint of bond-breaking/forming steps.

Catalyst

A substance that increases the reaction rate by providing an alternative pathway with lower activation energy.

Enzymes

Biological catalysts that significantly speed up biochemical reactions.

Reaction Mechanism

Series of steps detailing how a reaction occurs at the molecular level.

Proper Orientation

Correct alignment of reactant particles during a collision for effective reactions.

Factors Influencing Reaction Rate

Kinetic energy, concentration, and temperature impact the rate of reactions.

Activation Energy vs. Free Energy

Activation energy is unrelated to Gibbs free energy; different Ea can give same ΔG.

Higher Kinetic Energy

Increases the chance of effective collisions in a reaction.

Rate Constant (k)

A constant that appears in the rate law, specific to the reaction at a given temperature.

Molecular Orders (w, x, y)

Determined experimentally, these reveal how reactant concentrations affect reaction rates.

Local Minima in Energy Diagrams

Represents intermediates in a reaction mechanism.

Local Maxima in Energy Diagrams

Represents transition states in a reaction mechanism.

Influence of Structural Changes

Refers to the changes needed in reactants that influence activation energy.

Reaction Rate Expression

Formulated as r=k⋅[A]w⋅[B]x⋅[C]y.

Alternative Pathways

Paths offered by catalysts that lower activation energy without changing ΔG.

Increased Interaction Probability

Catalysts increase the interaction likelihood between reactants.

Biochemical Reactions

Reactions that are sped up by enzymes, the biological catalysts.

Rate of Reaction

The speed at which reactants convert into products.

Effective Collision

Collision with sufficient energy and correct orientation for reaction.

Energy Diagrams

Graphs that show the energy changes during a chemical reaction.

Factors Enhancing Reaction Rates

Include increased concentration, temperature, and kinetic energy.

Impact of Temperature on Particles

Higher temperature results in faster movement of particles.

Efficiency of Enzymes

Enzymes can increase reaction rates by factors of 1000-100,000.

Biological Catalysts

Enzymes that facilitate biochemical reactions without being consumed.

Hope's Reactions

Refers to the spontaneity not indicating speed of these reactions.

Proof of Catalysts

They do not alter ΔG or equilibrium concentrations of reactions.

Chemical Reaction Dynamics

Study of how and why reactions occur and proceed.

Kinetic Energy Relationship

Directly relates to temperature and reflects the movement of particles.

Effective Collision Requirements

Require proper kinetic energy and orientation to result in a reaction.

Energy Requirement for Reactions

Activation energy is essential for starting the chemical processes.

Sum of Individual Orders

Overall order of a reaction is the total of individual reactant orders.

Determination of Orders

Orders are typically determined through experimental means.