11.5 分解反应

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  分解反应

  

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  How does a decomposition reaction work?
  ::分解反应如何起作用?

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  Antoine Lavoisier is widely known as the “father of modern chemistry .” He was one of the first to study in detail. Lavoisier reacted mercury with oxygen to form mercuric oxide as part of his studies on the composition of the atmosphere. He was then able to show that the decomposition of mercuric oxide produced mercury and oxygen. The diagram above shows the apparatus used by Lavoisier to study the formation and decomposition of mercuric oxide.
  ::安托万·拉沃伊瑟(Antoine Lavoisier)被广泛称为“现代化学之父 ” 。 他是最早进行详细研究的国家之一。拉沃伊瑟(Lavoisier)用氧气对汞进行反应,形成汞氧化物,作为其关于大气构成的研究的一部分,然后他能够证明汞氧化物的分解产生了汞和氧。上面的图表显示了拉沃伊瑟(Lavoisier)用于研究汞氧化物形成和分解的仪器。

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  Decomposition Reactions
  ::分解反应

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  A is a reaction in which a breaks down into two or more simpler substances . The general form of a decomposition reaction is:
  ::A是分解成两种或两种以上较简单的物质的一种反应。

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  $$\begin{array}{r}AB\to A+B\end{array}$$

  
  ::ABA+B

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  Most decomposition reactions require an input of energy in the form of , light, or electricity. 
  ::大多数分解反应需要以光或电的形式投入能量。

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  Binary compounds are compounds composed of just two . The simplest kind of decomposition reaction is when a binary compound decomposes into its elements. Mercury(II) oxide, a red solid, decomposes when heated to produce mercury and oxygen .
  ::二进制化合物由二进制化合物组成。最简单的分解反应是当二进制化合物分解成其元素时。二进制化合物氧化汞(II),红色固体,加热产生汞和氧时分解。

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  $$\begin{array}{r}2\text{HgO}(s)\to 2\text{Hg}(l)+{\text{O}}_2(g)\end{array}$$

  
  ::2HGO 2Hg(l)+O2(g)

  

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  Mercury(II) oxide is a red solid. When it is heated, it decomposes into mercury metal and oxygen gas.
  ::氧化汞是一种红固体,当加热时会分解成汞金属和氧气。

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  A reaction is also considered to be a decomposition reaction even when one or more of the products are still compounds. A metal carbonate decomposes into a metal oxide and carbon dioxide gas. For example, calcium carbonate decomposes into calcium oxide and carbon dioxide.
  ::即使一种或多种产品仍然是化合物,反应也被视为分解反应,碳酸金属分解成氧化金属和二氧化碳气体,例如碳酸钙分解成氧化钙和二氧化碳。

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  $$\begin{array}{r}{\text{CaCO}}_3(s)\to \text{CaO}(s)+{\text{CO}}_2(g)\end{array}$$

  
  ::CaCO3+CO2(g)

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  Metal hydroxides decompose on heating to yield metal oxides and water. Sodium hydroxide decomposes to produce sodium oxide and water.
  ::金属氢氧化物在加热后分解,产生金属氧化物和水,氢氧化钠分解,产生氧化钠和水。

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  $$\begin{array}{r}2\text{NaOH}(s)\to {\text{Na}}_2\text{O}(s)+{\text{H}}_2\text{O}(g)\end{array}$$

  
  ::2NaOH+NA2O+H2O(g)

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  Some unstable acids decompose to produce oxides and water. Carbonic decomposes easily at room temperature into carbon dioxide and water.
  ::一些不稳定的酸分解产生氧化物和水,碳在室温下很容易分解成二氧化碳和水。

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

  
  ::H2CO3(aq)CO2(g)+H2O(l)

   

    

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  Sample Problem: Decomposition Reactions
  ::抽样问题:分解反应

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  When an electric current is passed through pure water, it decomposes into its elements. Write a balanced equation for the decomposition of water.
  ::当电流经过纯净水时, 电流会分解成其元素。 为水分解写一个平衡的方程 。

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  Step 1: Plan the problem.
  ::第1步:规划问题。

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  Water is a binary compound composed of hydrogen and oxygen. The hydrogen and oxygen gases produced in the reaction are both diatomic molecules.
  ::水是一种由氢和氧组成的二元化合物,反应中产生的氢和氧气体是二原子分子。

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  Step 2: Solve.
  ::步骤2:解决。

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  The skeleton (unbalanced) equation:
  ::骨骼(不平衡)等式:

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  $$\begin{array}{r}{\text{H}}_2\text{O}(l)\stackrel{\text{elec}}{\to }{\text{H}}_2(g)+{\text{O}}_2(g)\end{array}$$

  
  ::H2O(l)elecH2(g)+O2(g)

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  Note the abbreviation “elec” above the arrow to indicate the passage of an electric current to initiate the reaction. Balance the equation.
  ::注意箭头上方的缩略语“elec”,以表示电流的通过以引发反应。平衡方程式。

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  $$\begin{array}{r}2{\text{H}}_2\text{O}(l)\stackrel{\text{elec}}{\to }2{\text{H}}_2(g)+{\text{O}}_2(g)\end{array}$$

  
  ::2H2O(l)elec2H2(g)+O2(g)

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  Step 3: Think about your result.
  ::步骤3:想想你的结果。

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  The products are elements and the equation is balanced.
  ::产品是元素,等式是平衡的。

   

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  How does an airbag explode at just the right time in the event of a car accident? Learn more in this simulation: 
  ::如果发生车祸,气囊怎么会在正确的时间爆炸?在这个模拟中学到更多:

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  Summary
  ::摘要

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  • A definition of decomposition reaction and example reactions are given.
    ::给出了分解反应和示例反应的定义。

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  Review
  ::回顾

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  1. What is a decomposition reaction?
     ::什么是分解反应?
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  2. What is usually needed for a decomposition reaction to take place?
     ::发生分解反应通常需要什么?
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  3. Are elements always the product of a decomposition reaction?
     ::元素总是分解反应的产物吗?