AP Chemistry Flashcards: Introduction to Le Châtelier’s Principle
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 10 cards to help you master important concepts.
What is Le Châtelier's principle used for?
Le Châtelier's principle is used to predict the response of a system at equilibrium when it is subjected to an external stress.
Card 1 of 10
All Flashcards (10)
What is Le Châtelier's principle used for?
Le Châtelier's principle is used to predict the response of a system at equilibrium when it is subjected to an external stress.
A student observes a color change after adding a chemical to a solution at equilibrium. What principle can be used to explain this observation?
Le Châtelier's principle can be used to explain the color change, as it predicts how the system shifts in response to the stress of adding a species.
Define 'external stress' as it relates to chemical equilibrium.
An external stress is a change imposed on a system at equilibrium, such as a change in concentration, temperature, or pressure, that disrupts the equilibrium state.
Besides changes in concentration, temperature, or pressure, what is another type of stress mentioned that can affect an equilibrium system?
Dilution, which involves adding a solvent to decrease the concentration of all aqueous species, is another stress that can affect a system.
According to Le Châtelier's principle, how does a system at equilibrium respond to a stress?
The system will respond in a way that counteracts the external stress, shifting to re-establish a new equilibrium.
What is meant by 'addition/removal of a species' in the context of Le Châtelier's principle?
This refers to changing the concentration or amount of a reactant or product within the equilibrium system.
For a gas-phase system, what two related physical changes can act as a stress?
For a gas-phase system at equilibrium, a change in volume or a change in pressure can act as a stress.
List three types of stresses that can be applied to a system at equilibrium.
Three common stresses are the addition/removal of a species, a change in temperature, or a change in volume/pressure for a gas-phase system.
Name two experimentally measurable properties of a solution that Le Châtelier's principle can predict changes in.
Le Châtelier's principle can be used to predict the effect of a stress on properties like the pH or color of a solution.
What is the overall goal of the system's response to a stress?
The goal is to partially oppose the imposed change and establish a new state of equilibrium.