平衡常数的计算和解释取决于化学反应是均匀平衡还是非均相平衡。所有产物和反应物处于相同相,以在均相平衡下进行反应。例如,一切都可以是液体,或者所有物种都可以是气体。对于达到异质平衡的反应,存在多个相。通常仅存在两相,例如液体和气体或固体和液体。平衡表达中省略了固体。平衡常数的重要性对于任何给定温度,平衡常数只有一个值。如果反应发生的温度发生变化,则Kc仅发生变化。您可以根据平衡常数是大还是小来对化学反应做出一些预测。如果Kc的值非常大,那么平衡有利于右边的反应,并且产品比反应物更多。该反应可以说是“完全的”或“定量的”。如果平衡常数的值很小,则平衡有利于向左反应,反应物多于产物。如果Kc的值接近零,则可以认为反应不发生。如果正向反应和反向反应的平衡常数值几乎相同,那么反应大约可能在一个方向上进行,而另一个反应物和产物的量几乎相等。这种类型的反应被认为是可逆的

澳大利亚国立大学生物学Essay代写:平衡常数Kc及其计算方法

The calculation and interpretation of the equilibrium constant depends on whether the chemical reaction involves homogeneous equilibrium or heterogeneous equilibrium. All of the products and reactants are in the same phase for a reaction at homogeneous equilibrium. For example, everything could be a liquid or all the species could be gases. More than one phase is present for reactions that reach heterogeneous equilibrium. Usually only two phases are present, such as liquids and gases or solids and liquids. Solids are omitted from the equilibrium expression.
Significance of the Equilibrium Constant For any given temperature, there is only one value for the equilibrium constant. Kc only changes if the temperature at which the reaction occurs changes. You can make some predictions about the chemical reaction based on whether the equilibrium constant is large or small. If the value for Kc is very large, then the equilibrium favors the reaction to the right and there are more products than reactants. The reaction may be said to be “complete” or “quantitative.” If the value for the equilibrium constant is small, then the equilibrium favors the reaction to the left and there are more reactants than products. If the value of Kc approaches zero the reaction may be considered not to occur. If the values for the equilibrium constant for the forward and reverse reaction are nearly the same then the reaction is about as likely to proceed in one direction and the other and the amounts of reactants and products will be nearly equal. This type of reaction is considered to be reversible.

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