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7: Equilibrium Fundamentals

  • Page ID
    501071
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    • 7.0: Introduction
      Equilibrium by Design: Self-Assembled Monolayers
    • 7.1: The Dynamic Nature of Equilibria
      Chemical equilibrium occurs when the rates of the forward and reverse reactions are equal. Equilibrium is dynamic, meaning that both reactions continue to occur, but the counter-balanced rates result in unchanging concentrations of reactants and products. The concept of equilibrium applies to very many natural systems, including chemical reactions, phase changes, drug-receptor binding, and beyond.
    • 7.2: Reactant Quotients and Equilibrium Constants
      For a given chemical reaction, the equilibrium constant, K, has a characteristic value at a given temperature. K is defined by the equilibrium constant expression, which is the ratio of the activities (via concentrations or partial pressures) of (all) products to (all) reactants, with each raised to its respective stoichiometric coefficient. The reaction quotient, Q, is defined by an expression with the same form, but with the activities from at any point in a reaction.
    • 7.3: Equilibrium Calculations
      In equilibrium problems, we use concentrations or pressures at equilibrium to calculate Kc​ or Kp,​ or vice versa to determine values once a reaction reaches equilibrium. Changes in concentration (or pressure) follow the stoichiometric coefficients in the balanced equation. ICE (Initial, Change, Equilibrium) tables help organize equilibrium calculations.
    • 7.4: Shifting Equilibria - Le Chatelier’s Principle
      Le Chatelier’s Principle states that if a system at equilibrium is disturbed, it shifts predictably to counteract the disturbance as equilibrium is re-established. For example, adding or removing a reactant or product causes a shift that partly consumes or produces that species. For a volume change, the direction depends on the relative number of gaseous reactant and product molecules. Temperature changes alter K, but the principle correctly predicts which way the reaction shifts.
    • 7.E: Equilibrium Fundamentals (Exercises)
      Working through the end-of-chapter problems is an important part of mastering chemical equilibrium. These questions help you assess your understanding of core principles, practise applying them to different systems, and refine your problem-solving strategies. Regular practice is important!


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