Reaction Rates and Equilibrium

A collection of flashcards focusing on the key concepts from the lecture on reaction rates and equilibrium, including definitions, principles, and examples.

What is a spontaneous process?

A spontaneous process takes place naturally with no apparent cause or stimulus.

What is a nonspontaneous process?

A nonspontaneous process takes place only as a result of some cause or stimulus.

What is an exergonic process?

An exergonic process gives up energy as it occurs and is represented with energy on the right side of the equation.

What is an endergonic process?

An endergonic process gains or absorbs energy as it takes place and is depicted with energy on the left side of the equation.

How are energy and entropy related to spontaneity?

Processes are spontaneous if energy decreases and entropy increases.

What is the definition of reaction rate?

The speed of a reaction, determined experimentally as the change in concentration of a reactant or product divided by the time required for that change.

What is the significance of molecular collisions in reactions?

Reactant particles must collide with one another, with sufficient energy and correct orientation, for a reaction to occur.

What is activation energy?

The energy required to start a spontaneous process and allows bonds in reactant molecules to break.

What is a catalyst?

A substance that changes reaction rates without being consumed in the reaction.

What is Le Châtelier's principle?

Le Châtelier's principle states that the position of an equilibrium shifts in response to changes in concentration and temperature.

What is an equilibrium constant (K)?

The numerical relationship between reactant and product concentrations in a reaction at equilibrium, with a constant value unless there is a temperature change.

How does the concentration of reactants influence reaction rates?

Increasing the concentration of reactants typically increases the reaction rate due to the increased likelihood of collisions.

How does temperature affect reaction rates?

An increase in temperature raises the average kinetic energy of molecules, leading to more frequent and effective collisions, thus increasing the reaction rate.

What constitutes an effective collision?

An effective collision is one that leads to a reaction occurring between colliding molecules, requiring the right amount of energy and proper orientation.

What is indicated by a large value of the equilibrium constant (K)?

A large value of K indicates that the equilibrium position favors the products.

What happens to the position of equilibrium when reactants are added?

The equilibrium position shifts toward the products.

What is a stable substance?

A stable substance does not undergo spontaneous changes under the surrounding conditions.

What happens to equilibrium when the temperature of an endothermic reaction is increased?

The equilibrium position shifts toward the products, as heat is considered a reactant.