Online Resources for Teaching and Learning Chemistry

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Resource Topic: Equilibrium

• LeChatlier's Principle

  Concept Tests

  • Chemical Equilibria Concept Test

    Concept Test

    These equilibrium based concept tests can be used as part of in-class activities to help students reason about equilibrium concepts.

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  Tutorials

  • Concentration

    Tutorial

    Discusses how LeChatelier's principle applies when the "stress" to a system at equilibrium is a change in concentration of products or reactants.

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  • LeChatlier's Principle: Hemoglobin scenario

    Tutorial

    Chemists use LeChatelier's principle to reason qualitatively about the influence of changes in concentration, temperature or pressure on systems that are at equilibrium. This movie describes the hemoglobin scenario…

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  • Using LeChatlier's Principle

    Tutorial

    Introduces the general formulation of Le Chatlier's principle. LeChatlier's principle is a general and very powerful framework for making predictions about the effects of stress is on chemical systems.

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  • Reversible Reactions

    Tutorial

    Gives a more general overview of reversible reactions and the concept of chemical equilibrium.

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  • Temperature

    Tutorial

    LeChatelier's principle is used to determine the response of a system at chemical equilibrium to an applied stress. This tutorial looks at how changes in temperature influence systems at equilibrium.

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  • Volume/Pressure

    Tutorial

    LeChatelier's principle is a qualitative approach to reason about how systems at equilibrium will react to changes. This tutorial looks at how changes in volume or pressure influence systems at equilibrium.

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  Virtual Labs

  • Cobalt Chloride and LeChatlier’s Principle

    Virtual Lab

    In this activity, students safely explore the equilibrium reaction of the cobalt chloride reaction.

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• Progress of Reaction

  Concept Tests

  • Chemical Equilibria Concept Test

    Concept Test

    These equilibrium based concept tests can be used as part of in-class activities to help students reason about equilibrium concepts.

    Get Info Go

  Tutorials

  • Comparing Q to K to determine shift

    Tutorial

    If a system has not reached chemical equilibrium, we can use the reaction quotient, Q, and the equilibrium constant, K to determine whether the reaction will shift towards products (right) or reactants (left).

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  • Equilibrium is dynamic

    Tutorial

    Once a system has reached chemical equilibrium, reactions still occur. Equilibrium systems are dynamic. Although the concentrations have reached a steady state, both the forward and reverse reactions continue to…

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  • Comparing Q to K Tutorial: Hemoglobin scenario

    Tutorial

    In this movie, we describe the hemoglobin scenario from the perspective of comparing Q (a measure of the current state of a reaction) to K (a measure of the equilibrium state of a reaction).

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  • Law of mass action (Q=K)

    Tutorial

    Chemical equilibrium systems obey the law of mass action. This law states that the reaction quotient, Q, will be equal to a constant when a system reaches chemical equilibrium. This tutorial explains the law of…

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  • Manipulating K and chemical reactions

    Tutorial

    This tutorial looks at how Q and K change when we manipulate a chemical reaction by doubling it, reversing it, or combining it with another reaction.

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  • Progress of reaction (Q)

    Tutorial

    A central concept that underlies all of the reasoning we will be doing about chemical equilibrium systems is the progress of reaction.This tutorial defines and examines the progress of reaction.

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  • Q for heterogeneous reactions

    Tutorial

    This tutorial discusses how to determine which concentrations appear in the law of mass action when calculating the reaction quotient Q.

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  • Equilibrium and thermodynamics (K and ΔG)

    Tutorial

    This tutorial looks at the relation between the equilibrium state reached by reversible reactions and the thermodynamics of those reactions.

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• Equilibrium Calculations

  Concept Tests

  • Chemical Equilibria Concept Test

    Concept Test

    These equilibrium based concept tests can be used as part of in-class activities to help students reason about equilibrium concepts.

    Get Info Go

  Scenario-Based Activities

  • DNA Binding Dyes Scenario

    Scenario-Based Activity

    This activity explores the equilibrium of dyes that self-assemble into DNA templates. Students use knowledge of equilibrium and quantitative spectroscopy to explore different dyes that bind selectively to DNA molecules.…

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  Simulations

  • Equilibrium Simulation

    Simulation

    This applet is similar to the stoichiometry simulation but applies to chemical reactions that do not go to completion. The calculation of the equilibrium state of such reactions is typically covered months after…

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  • Acclimatization on Mt. Everest

    Simulation

    To get to the top of the mountain before winter arrives, students must derive an equation that relates the necessary amount of hemoglobin to the partial pressure of oxygen at the current and next camp.

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  Tutorials

  • Quantitative Equilibrium: Hemoglobin scenario

    Tutorial

    This movie describes the hemoglobin scenario from the perspective of quantitative calculations.

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  • Calculations for intermediate values of K

    Tutorial

    How do we determine final concentrations for equilibrium systems? When reactions are reversible, neither the forward nor the backward reaction will progress to completion. This page demonstrates quantitative calculations…

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  • Calculations for large or small values of K

    Tutorial

    Many reversible reactions have large or small values for their equilibrium constant, K. That is, one reaction (either the forward or the reverse) is much stronger than the other reaction. For instance, most…

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  • Limiting reagents using ICE tables

    Tutorial

    This tutorial demonstrates quantitative calculations to determine final concentrations in reactions that go to completion.

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  • Overview (Equilibrium vs. limiting reagents)

    Tutorial

    A general introduction to a number of techniques used to determine how chemical reactions alter the concentrations of chemical species.

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  • Shifting starting position to simplify calculations

    Tutorial

    Quantitative calculations on chemical equilibrium systems often lead to rather tedious algebra involving cubic or high-order polynomial equations. Since all possible states of a chemical reaction (e.g., values…

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  Virtual Labs

  • DNA Binding Problem

    Virtual Lab

    In this activity, students explore equilibrium constants in biochemical systems by measuring the binding constant of a DNA-Dye reaction.

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• Common Ion Effect

  Autograded Virtual Labs

  • Solubility and the Common Ion Effect

    Autograded Virtual Lab

    Determine the concentration of an unknown NaCl solution using the common ion effect.

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  • Metal Ligand Binding

    Autograded Virtual Lab

    Use silver chloride to determine the binding constant for a metal ligand complex.

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