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7: Chemical Reactions - Energy, Rates, and Equilibrium

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    • 7.1: Energy and Chemical Bonds
      Energy is the ability to do work. Heat is the transfer of energy due to temperature differences. Energy and heat are expressed in units of joules.
    • 7.2: Heat Changes during Chemical Reactions
      Heat transfer is related to temperature change. Heat is equal to the product of the mass, the change in temperature, and a proportionality constant called the specific heat.
    • 7.3: Exothermic and Endothermic Reactions
      Atoms are held together by a certain amount of energy called bond energy. Chemical processes are labeled as exothermic or endothermic based on whether they give off or absorb energy, respectively.
    • 7.4: Why Do Chemical Reactions Occur? Free Energy
      One of the major goals of chemical thermodynamics is to establish criteria for predicting whether a particular reaction or process will occur spontaneously. We have developed one such criterion, the change in entropy of the universe. This is not particularly useful and a criterion of spontaneity that is based solely on the state functions of a system would be much more convenient and is provided by a new state function: the Gibbs free energy.
    • 7.5: How Do Chemical Reactions Occur? Reaction Rates
    • 7.6: Effects of Temperature, Concentration, and Catalysts on Reaction Rates
      By their nature, some reactions occur very quickly, while others are very slow. However, certain changes in the reaction conditions can have an effect on the rate of a given chemical reaction. Collision theory can be utilized to explain these rate effects.
    • 7.7: Reversible Reactions and Chemical Equilibrium
    • 7.8: Equilibrium Equations and Equilibrium Constants
      Every chemical equilibrium can be characterized by an equilibrium constant, known as Keq. The Keq and KP expressions are formulated as amounts of products divided by amounts of reactants; each amount (either a concentration or a pressure) is raised to the power of its coefficient in the balanced chemical equation. Solids and liquids do not appear in the expression for the equilibrium constant.
    • 7.9: Le Chatelier’s Principle- The Effect of Changing Conditions on Equilibria
      Le Chatelier's principle addresses how an equilibrium shifts when the conditions of an equilibrium are changed. The direction of shift can be predicted for changes in concentrations, temperature, or pressure. Catalysts do not affect the position of an equilibrium; they help reactions achieve equilibrium faster.

    7: Chemical Reactions - Energy, Rates, and Equilibrium is shared under a CC BY-NC-SA 3.0 license and was authored, remixed, and/or curated by LibreTexts.

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