16.18 分子和音量等同

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  分子和音量等同

  

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  “Just a little rain...”
  ::"只是点小雨..."

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  One of the unfortunate by-products of our industrialized society is rain. Sulfur dioxide from burning coal and nitric oxides from vehicle emissions both form acids. When these acids react with limestone (calcium carbonate), reactions occur that dissolve the limestone and release water and carbon dioxide. Over a period of time, serious damage is caused to the structures.
  ::我们工业化社会不幸的副产品之一是降雨,燃烧煤炭和汽车排放的氮氧化物所产生的二氧化硫,两者都是形式酸。当这些酸与石灰岩(碳酸钙)发生反应时,反应会溶解石灰岩,释放水和二氧化碳。 在一段时间内,结构受到严重破坏。

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  Molecular and Ionic Equations
  ::分子和音量等同

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  When are dissolved into water, the polar water molecules break apart the solid crystal lattice, resulting in the hydrated being evenly distributed through the water. This process is called and is the reason that all ionic compounds are strong electrolytes. When two different ionic compounds that have been dissolved in water are mixed, a may occur between certain pairs of the hydrated ions.
  ::当溶解到水中时,极地水分子分裂出固体晶体板,导致水分在水中均匀分布。这个过程被称为所有离子化合物都是强电解液,并且是所有离子化合物都是电解液的原因。当水中溶解的两种不同的离子化合物混合在一起时,水分离子的某些对子之间可能会发生。

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  Consider the that occurs when a solution of sodium chloride is mixed with a solution of silver nitrate.
  ::考虑当氯化钠溶液与硝酸银溶液混合时发生的情况。

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  $$\begin{array}{r}\text{NaCl}(aq)+{\text{AgNO}}_3(aq)\to {\text{NaNO}}_3(aq)+\text{AgCl}(s)\end{array}$$

  
  ::Nacl(aq)+AgNO3(aq)+NaNO3(aq)+AgCl(s)

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  The driving force behind this reaction is the formation of the silver chloride precipitate (see Figure ).
  ::这种反应背后的驱动力是氯化银沉淀物的形成(见图 )。

  

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  The white silver chloride precipitate instantly forms when a solution of silver nitrate is added to a solution of sodium chloride.
  ::在氯化钠溶液中添加硝酸银溶液时,白氯化银即刻形成。

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  This is called a molecular equation . A molecular equation is an equation in which the formulas of the compounds are written as though all substances exist as molecules. However, there is a better way to show what is happening in this reaction. All of the aqueous compounds should be written as ions because they are present in the water as separated ions because of their dissociation.
  ::这被称为分子方程。分子方程是一个方程,其中化合物的公式写成,仿佛所有物质都作为分子存在。然而,有一个更好的方法可以显示在这种反应中正在发生的情况。所有水化合物应该写成离子,因为它们由于分离而存在于水中,作为分离离子存在于水中。

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  $$\begin{array}{r}{\text{Na}}^{+}(aq)+{\text{Cl}}^{-}(aq)+{\text{Ag}}^{+}(aq)+{\text{NO}}_3^{-}(aq)\to {\text{Na}}^{+}(aq)+{\text{NO}}_3^{-}(aq)+\text{AgCl}(s)\end{array}$$

  
  ::Na+(aq)+Cl-(aq)+Ag+(aq)+Ag+(aq)+NO3-(aq)+(aq)+NO3-(aq)+AgCl(s)

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  This equation is called an ionic equation , an equation in which dissolved ionic compounds are shown as free ions.
  
  ::这一方程式称为离子方程式,其中溶解的离子化合物显示为自由离子。

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  Some other double-replacement reactions do not produce a precipitate as one of the products. The production of a and/or a molecular such as water may also drive the reaction. For example, consider the reaction of a solution of sodium carbonate with a solution of hydrochloric acid (HCl). The products of the reaction are aqueous sodium chloride, carbon dioxide, and water. The balanced molecular equation is:
  ::例如,考虑碳酸钠溶液与盐酸溶液的反应。反应的产物是水氯化钠、二氧化碳和水。平衡分子方程式是:

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  $$\begin{array}{r}{\text{Na}}_2{\text{CO}}_3(aq)+2\text{HCl}(aq)\to 2\text{NaCl}(aq)+{\text{CO}}_2(g)+{\text{H}}_2\text{O}(l)\end{array}$$

  
  ::Na2CO3(aq)+2HCl(aq)+2NaCl(aq)+CO2(g)+H2O(l)

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  The ionic equation is:
  ::离子方程是:

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  $$\begin{array}{r}2{\text{Na}}^{+}(aq)+{\text{CO}}_3^{2-}(aq)+2{\text{H}}^{+}(aq)+2{\text{Cl}}^{-}(aq)\to 2{\text{Na}}^{+}(aq)+2{\text{Cl}}^{-}(aq)+{\text{CO}}_2(g)+{\text{H}}_2\text{O}(l)\end{array}$$

  
  ::2Na+(aq)+CO32-(aq)+2H+2H+(aq)+2Cl+2Cl-(aq)+2Cl+2Cl+(aq)+CO2(g)+H2O(l)

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  A single-replacement reaction is one in which an replaces another element in a compound. An element is in either the solid, , or gas state and is not an ion. The example below shows the reaction of solid magnesium metal with aqueous silver nitrate to form aqueous magnesium nitrate and silver metal.
  ::单重置反应是一种替换化合物中另一个元素的反应,一种元素处于固体或气体状态,而不是离子。下面的例子显示了固体镁金属与水银硝酸盐形成水镁硝酸盐和银金属的反应。

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  Balanced molecular equation:
  ::平衡分子方程:

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  $$\begin{array}{r}\text{Mg}(s)+2{\text{AgNO}}_3(aq)\to {\text{Mg(NO}}_3{)}_2(aq)+2\text{Ag}(s)\end{array}$$

  
  ::Mg(s)+2AgNO3(aq) Mg(NO3)(2)(aq)+2Ag(s)

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  Ionic equation:
  ::音量方程式 :

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  $$\begin{array}{r}\text{Mg}(s)+2{\text{Ag}}^{+}(aq)+2{\text{NO}}_3^{-}(aq)\to {\text{Mg}}^{2+}(aq)+2{\text{NO}}_3^{-}(aq)+2\text{Ag}(s)\end{array}$$

  
  ::Mg+2Ag+(aq)+2NO3-(aq)+Mg2+(aq)+2NO3+(aq)+2Ag

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  This type of single-replacement reaction is called a metal replacement. Other common categories of are hydrogen replacement and halogen replacement. 
  ::这种类型的单更换反应称为金属替换,其他常见类别是氢替换和卤素替换。

   

   

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  Summary
  ::摘要

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  • Examples of molecular and ionic equations are shown.  
    ::列举了分子和离子等式的例子。

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  Review
  ::回顾

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  1. What do the small letters after the compounds indicate?
     ::化合物后的小字母表示什么?
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  2. Why is it important to show the state of each compound?
     ::为什么一定要显示每个化合物的状态?
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  3. What do ionic equations tell us?
     ::离子方程式告诉我们什么?