章节大纲

  • Jigsaw puzzle pieces scattered on a table, representing disorder before assembly.

    What will it look like?
    ::它会是什么样子?

    When the pieces of a jigsaw puzzle are dumped from the box, the pieces naturally hit the table in a very random pattern. In order to put the puzzle together, a great deal of work must be done to overcome the natural disorder of the pieces. The pieces need to be turned right-side up, then sorted by color or edge (some people like to put the border together first). Then comes the challenge of finding the exact spot of each piece of the puzzle in order to get the final organized picture.
    ::当拼图的碎片被从盒子中丢弃时, 拼图的碎片自然会以一种非常随机的方式击中桌子。 为了拼图的拼图拼凑在一起, 需要做大量的工作来克服拼图的自然混乱。 拼图的碎片需要向右倾斜, 然后按颜色或边缘进行分类( 一些人喜欢先把边框拼凑起来 ) 。 接下来的挑战就是找到拼图中每块的准确位置, 才能获得最后的有条理的图片 。

    Entropy
    ::信孔号

    There is a tendency in nature for systems to proceed toward a state of greater disorder or randomness. Entropy is a measure of the degree of randomness or disorder of a system . Entropy is an easy concept to understand when thinking about everyday situations. The entropy of a room that has been recently cleaned and organized is low. As time goes by, it likely will become more disordered and thus its entropy will increase (see Figure ). The natural tendency of a system is for its entropy to increase.
    ::系统在性质上倾向于走向更大的混乱或随机状态。 通缩度是系统随机性或紊乱程度的度量。 通缩度在思考日常情况时是一个容易理解的概念。 最近清理和整理过的房间的通缩率很低。 随着时间流逝,它可能会变得更加混乱,因此其通缩率会增加(见图 )。 系统的自然趋势是其通缩率会增加。

    Comparison of an organized room (A) with low entropy and a messy room (B) with high entropy.

    The messy room on the right has more entropy than the highly ordered room on the left.
    ::右侧的乱七八糟的房间比左侧的高级订制的房间 更具有共性

    also tend to proceed in such a way as to increase the total entropy of the system. How can you tell if a certain reaction shows an increase or a decrease in entropy? The molecular state of the reactants and products provide certain clues. The general cases below illustrate entropy at the molecular level.
    ::反应物和产品的分子状态也提供了某些线索。下面的一般案例说明了分子层次的通缩情况。

    1. For a given substance , the entropy of the state is greater than the entropy of the solid state. Likewise, the entropy of the is greater than the entropy of the liquid. Therefore, entropy increases in processes in which solid or liquid reactants form gaseous products. Entropy also increases when solid reactants form liquid products.
      ::对于一种特定物质,状态的酶大于固态的酶。同样,该物质的酶大于液体的酶。因此,固体或液体反应剂形成气体产品的过程的酶增加。当固体反应剂形成液体产品时,则该物质的酶也增加。
    2. Entropy increases when a substance is broken up into multiple parts. The process of dissolving increases entropy because the solute particles become separated from one another when a solution is formed.
      ::当一种物质分解成多个部分时,共性会增加。溶解过程会增加共性,因为溶液形成时溶液粒子会相互分离。
    3. Entropy increases as temperature increases. An increase in temperature means that the particles of the substance have greater . The faster moving particles have more disorder than particles that are moving more slowly at a lower temperature.
      ::随着温度的上升,信封会增加。温度的增加意味着该物质的粒子会更大。移动速度更快的粒子比在较低温度下移动速度较慢的粒子有更大的紊乱。
    4. Entropy generally increases in reactions in which the total number of product molecules is greater than the total number of reactant molecules. An exception to this rule is when a gas is being produced from nongaseous reactants.
      ::产品分子总数大于反应分子总数的反应普遍增加,这一规则的一个例外是,一种气体是由非气体反应剂产生的。

    The examples below will serve to illustrate how the entropy change in a reaction can be predicted.
    ::以下实例将有助于说明如何预测反应中的星体变化。

    Cl 2 ( g ) → Cl 2 ( l )
    ::Cl2(g) Cl2(l)

    The entropy is decreasing because a gas is becoming a liquid.
    ::由于气体正在变成液体,该酶正在下降。

    CaCO 3 ( s ) → CaO ( s ) + CO 2 ( g )
    ::CaCO3+CO2(g)

    The entropy is increasing because a gas is being produced and the number of molecules is increasing.
    ::由于正在生产一种气体,而分子数量也在增加,所以酶正在增加。

    N 2 ( g ) + 3 H 2 ( g ) → 2 NH 3 ( g )
    ::N2(g)+3H2(g)=2NH3(g)

    The entropy is decreasing because four total reactant molecules are forming two total product molecules. All are gases.
    ::酶正在下降,因为四个总反应分子组成两个总产品分子,都是气体。

    AgNO 3 ( a q ) + NaCl ( a q ) → NaNO 3 ( a q ) + AgCl ( s )
    ::AGNO3(aq)+NaCl(aq)+NaNO3(aq)+AgCl(s)

    The entropy is decreasing because a solid is formed from aqueous reactants.
    ::由于固体是由水反应器形成的,所以酶正在下降。

    H 2 ( g ) + Cl 2 ( g ) → 2 HCl ( g )
    ::H2(g) +Cl2(g) +Cl2(g)

    The entropy change is unknown (but likely not zero), because there are equal numbers of molecules on both sides of the equation and all are gases.
    ::由于方程两侧的分子数量相等,所有分子都是气体,所以还不知道酶变化情况(但可能不是零),因为方程两侧的分子数量相等。

     

     

     Summary
    ::摘要

    • Entropy is defined.
      ::信封被定义 。
    • Situations involving entropy changes are described.
      ::说明涉及星体变化的情况。

    Review
    ::回顾

    Indicate whether entropy increases or decreases in each of the following situations:
    ::说明下列每一种情况中的酶增减情况:

    1. The jigsaw puzzle is taken apart and put back in the box.
      ::拼图被拆开 重新放回盒子里
    2. Clothes are folded and put away.
      ::衣服被折叠并收起来。
    3. ice  → steam.
      ::冰 蒸汽 冰 蒸汽 冰 蒸汽 冰 蒸汽 冰 蒸汽 蒸汽 冰 蒸汽 蒸汽 蒸汽
    4. Pb(NO 3 ) 2 ( a q ) + 2 KI ( a q ) → PbI 2 ( s ) + 2 KNO 3 .
      ::P(NO3)(aq)+2KI(aq)PbI2(s)+2KNO3。