chemical equilibrium

简明释义

化学平衡

英英释义

例句

1.Le Chatelier's principle helps predict how a change in conditions will affect chemical equilibrium.

勒夏特列原理有助于预测条件变化如何影响化学平衡。

2.When temperature is increased, the position of chemical equilibrium may shift to favor the endothermic reaction.

当温度升高时，化学平衡的位置可能会向有吸热反应的一方移动。

3.In a closed system, the reaction will eventually reach chemical equilibrium, where the rate of the forward reaction equals the rate of the reverse reaction.

在一个封闭系统中，反应最终会达到化学平衡，此时正反应的速率等于逆反应的速率。

4.The concentration of reactants and products remains constant at chemical equilibrium.

在化学平衡状态下，反应物和产物的浓度保持不变。

5.Catalysts do not affect the position of chemical equilibrium, but they can speed up the time it takes to reach it.

催化剂不会影响化学平衡的位置，但可以加快达到平衡所需的时间。

作文

In the study of chemistry, one of the most important concepts is chemical equilibrium. This term refers to the state in which the concentrations of reactants and products remain constant over time in a reversible reaction. At this point, the rate of the forward reaction equals the rate of the reverse reaction, resulting in no net change in the system. Understanding chemical equilibrium is crucial for chemists as it helps predict the behavior of reactions under various conditions.To illustrate this concept, consider the synthesis of ammonia through the Haber process. The reaction can be represented as: N2(g) + 3H2(g) ⇌ 2NH3(g). In this reaction, nitrogen gas and hydrogen gas react to form ammonia. Initially, when the reactants are mixed, the concentration of ammonia is zero. As the reaction progresses, ammonia is produced, and its concentration increases. However, as the amount of ammonia builds up, the reverse reaction (the decomposition of ammonia back into nitrogen and hydrogen) also begins to occur. Eventually, the rates of the forward and reverse reactions become equal, and the system reaches chemical equilibrium.The position of chemical equilibrium can be influenced by several factors, including temperature, pressure, and the concentration of reactants or products. According to Le Chatelier's principle, if an external change is applied to a system at chemical equilibrium, the system will adjust itself to counteract that change and restore a new equilibrium state. For example, if the pressure is increased in the ammonia synthesis reaction, the system will shift towards the side with fewer gas molecules to reduce the pressure, thus favoring the formation of ammonia.Moreover, the concept of chemical equilibrium is not limited to gaseous reactions; it also applies to reactions in solution. For instance, consider the dissociation of acetic acid in water:CH3COOH ⇌ CH3COO− + H+. In this case, acetic acid partially ionizes in water, and the concentrations of the ions and undissociated acetic acid reach a stable ratio at chemical equilibrium. This equilibrium can be affected by changes in pH, temperature, and the presence of other ions in the solution.Understanding chemical equilibrium is also vital in industrial applications. Many chemical processes are designed to operate at or near equilibrium to maximize product yield. By adjusting reaction conditions, industries can optimize their production processes. For example, in the production of sulfuric acid via the Contact Process, maintaining the right conditions allows for higher yields of the desired product, demonstrating the practical importance of chemical equilibrium in real-world applications.In conclusion, chemical equilibrium is a fundamental concept in chemistry that describes a dynamic balance between reactants and products in reversible reactions. It is essential for predicting how reactions will behave under different conditions and has significant implications in both theoretical and practical chemistry. By mastering the principles surrounding chemical equilibrium, chemists can better understand and manipulate chemical reactions to achieve desired outcomes, whether in the laboratory or industry.

在化学研究中，最重要的概念之一是化学平衡。这个术语指的是在可逆反应中，反应物和产物的浓度随时间保持恒定的状态。在这一点上，正反应的速率等于逆反应的速率，从而导致系统没有净变化。理解化学平衡对化学家至关重要，因为它有助于预测反应在各种条件下的行为。为了说明这一概念，考虑通过哈伯法合成氨的反应。该反应可以表示为：N2(g) + 3H2(g) ⇌ 2NH3(g)。在这个反应中，氮气和氢气反应生成氨。最初，当反应物混合时，氨的浓度为零。随着反应的进行，氨的产生使其浓度增加。然而，随着氨的量不断增加，逆反应（氨分解回氮和氢）也开始发生。最终，正反应和逆反应的速率相等，系统达到化学平衡。化学平衡的位置可以受到多种因素的影响，包括温度、压力以及反应物或产物的浓度。根据勒夏特列原理，如果对处于化学平衡的系统施加外部变化，系统将调整自身以抵消该变化并恢复新的平衡状态。例如，如果在氨合成反应中增加压力，系统将向气体分子数较少的一侧移动以降低压力，从而有利于氨的形成。此外，化学平衡的概念不仅限于气体反应；它同样适用于溶液中的反应。例如，考虑醋酸在水中的离解：CH3COOH ⇌ CH3COO− + H+。在这种情况下，醋酸部分离解在水中，离子和未离解的醋酸的浓度在化学平衡时达到稳定比例。该平衡可以受到pH值、温度和溶液中其他离子的存在的影响。理解化学平衡在工业应用中也是至关重要的。许多化学过程被设计为在或接近平衡状态下运行，以最大化产品产量。通过调整反应条件，工业可以优化其生产过程。例如，在接触法生产硫酸的过程中，维持正确的条件可以实现更高的所需产品产量，展示了化学平衡在实际应用中的重要性。总之，化学平衡是化学中的一个基本概念，它描述了可逆反应中反应物和产物之间的动态平衡。它对于预测反应在不同条件下的行为至关重要，并对理论和实践化学都有重大影响。通过掌握围绕化学平衡的原则，化学家可以更好地理解和操控化学反应，以实现所需的结果，无论是在实验室还是工业中。