Chemical Equilibrium and Collision Theory Lecture Review

Vocabulary-style flashcards covering chemical equilibrium, collision theory, Le Chatelier's Principle, and reaction kinetics based on the lecture notes.

Equilibrium

A state in which the rates of the forward and reverse reactions are equal and the concentrations of the reactants and products remain constant.

Collision Theory

The principle that for a successful chemical reaction, particles must collide with both the correct orientation and sufficient energy.

Successful Collision Factors

The two requirements for a reaction to occur: 1) Correct orientation and 2) Sufficient energy.

Catalyst

A substance that speeds up a reaction by acting like a 'matchmaker' to orient particles correctly, increasing both forward and reverse reaction rates.

Temperature (Collision Theory)

Increasing this factor provides particles with more energy, leading to more frequent collisions and more collisions with enough energy to react.

Concentration (Collision Theory)

Increasing this factor speeds up a reaction by providing more particles in a given space, resulting in more frequent collisions.

Pressure (Collision Theory)

Increasing this factor for gases reduces the available space, which increases the frequency of collisions.

Surface Area (Collision Theory)

Increasing this factor allows for more exposed particles to interact, leading to an increased number of collisions.

$$K > 1$$

A condition indicating that the equilibrium favors the products.

$$K < 1$$

A condition indicating that the equilibrium favors the reactants.

$$K = 1$$

A condition indicating that the equilibrium mixture contains equal amounts of reactants and products.

Reaction Quotient ($Q$)

A value calculated using the same expression as the equilibrium constant ($K$), but using concentrations measured at any time during the reaction.

$$Q > K$$

A situation where there are too many products; the reaction must shift in the reverse direction (Left) to reach equilibrium.

$$Q < K$$

A situation where there are too many reactants; the reaction must shift in the forward direction (Right) to reach equilibrium.

Le Chatelier's Principle (Pressure)

An increase in pressure shifts the equilibrium toward the side of the reaction with fewer total moles of gas.

Le Chatelier's Principle (Temperature)

A change that shifts equilibrium away from added heat or towards removed heat; related to whether the reaction is exothermic or endothermic.

Iodine Clock Lab Relationship

The relationship between concentration and time is inverse, while the relationship between concentration and rate is linear.

Activated Complex

The peak point of potential energy on a reaction coordinate diagram where reactants are being converted to products.

Activation Energy ($E_a$)

The minimum amount of energy required for a chemical reaction to occur.

Exothermic Reaction

A reaction where the potential energy of the products is lower than the potential energy of the reactants, and heat is released ($\Delta H$ is negative).

Endothermic Reaction

A reaction where the potential energy of the products is higher than the potential energy of the reactants, and heat is absorbed ($\Delta H$ is positive).

Haber-Bosch Process

The equilibrium system used for ammonia production, represented by $3 H_2(g) + N_2(g) \rightleftharpoons 2 NH_3(g)$ with $\Delta H = -46\,kJ/mol$.

Yield

The amount of product produced; in exothermic reactions, lowering the temperature and increasing pressure can maximize this.