7.11 中立反应

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  中立反应

  

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  What is one of the most important characteristics of a referee? A referee must be neutral. They can’t favor one team over the other. In chemistry , being neutral means not being an or a . Pure water is an example of a neutral substance. In some , an acid and a base combine to form neutral products, including water. You’ll see how this happens when you read this article.
  ::裁判者最重要的特征之一是什么?裁判者必须是中立的,他们不能偏向于一个团队。在化学界,中立意味着不是一种或一种。纯水是中性物质的一个实例。在有些方面,酸和碱结合形成中性产品,包括水。当你阅读这篇文章时,你会看到这种情况是如何发生的。

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  Acids, Bases, and Ions
  ::酸、碱和离子酸

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  An acid is a that produces positive hydrogen (H ⁺ ) and negative ions when it dissolves in water. (Ions are atoms that have become charged by losing or gaining electrons.) Hydrochloric acid (HCl) is an example of an acid. When it dissolves in water, it produces positive hydrogen ions and negative chloride ions (Cl ^- ). This can be represented by the chemical equation :
  ::一种酸在溶解到水中时产生正氢(H+)和负离子(负离子)。 (离子是因丧失或获取电子而吸收的原子。 ) 一种酸的例子就是氢氯化酸。当酸溶解到水中时,会产生正氢离子和负氯化离子(Cl-)。这可以用化学方程式表示:

  HCl $\begin{array}{r}\stackrel{{\mathrm{H}}_2\mathrm{O}}{\to }\end{array}$ H ⁺ + Cl ^-

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  A base is a compound that produces negative hydroxide ions (OH ^- ) and positive metal ions when it dissolves in water. For example, when the base sodium hydroxide (NaOH) dissolves in water, it produces negative hydroxide ions and positive sodium ions (Na ⁺ ). This can be represented by the chemical equation:
  ::碱是一种在水中溶解时产生负氢氧化离子(OH)和正金属离子(正金属离子)的化合物。例如,当氢氧化钠(NaOH)在水中溶解时,产生负氢氧化离子和正离子(Na+)。这可以用化学方程式表示:

  NaOH $\begin{array}{r}\stackrel{{\mathrm{H}}_2\mathrm{O}}{\to }\end{array}$ OH ^- + Na ⁺

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  Q: If you were to combine acid and base solutions, what products do you think would be produced?
  ::问:如果你将酸和碱溶液结合起来, 你认为会生产哪些产品?

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  A: Combining acid and base solutions produces water and a neutral .
  ::A:将酸和碱性溶液结合起来可产生水和中性。

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  Reactions of Acids and Bases
  ::酸和碱反应

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  When an acid and a base react, the reaction is called a . That’s because the reaction produces neutral products. Water is always one product, and a salt is also produced. A salt is a neutral ionic compound. 
  ::当酸和碱反应时,反应被称为“a ” 。 这是因为反应产生中性产品。 水总是一种产品,盐也是一种产物。 盐是一种中性离子化合物。

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  Let’s see how a neutralization reaction produces both water and a salt, using as an example the reaction between solutions of hydrochloric acid and sodium hydroxide. The overall equation for this reaction is:
  ::让我们看看中性反应如何产生水和盐,以盐酸溶液和氢氧化钠溶液之间的反应为例。

  NaOH + HCl → H ₂ O and NaCl

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  Now let’s break this reaction down into two parts to see how each product forms.
  ::现在让我们将这种反应分成两部分,看看每种产品是如何形成的。

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  • Positive hydrogen ions from HCl and negative hydroxide ions from NaOH combine to form water. This part of the reaction can be represented by the equation:
    ::HCl的正氢离子和NaOH的负氢氧化离子结合形成水。

  H ⁺ + OH ^- → H ₂ O

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  • Positive sodium ions from NaOH and negative chloride ions from HCL combine to form the salt sodium chloride (NaCl), commonly called table salt. This part of the reaction can be represented by the equation:
    ::NaOH的正钠离子和HCL的负氯化离子合在一起形成氯化钠盐(NaCl),通常称为食盐。

  Na ⁺ + Cl ^- → NaCl

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  Another example of a neutralization reaction can be seen in the Figure .
  ::中性反应的另一个例子可见于图。

  

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  These antacid tablets contain the base calcium carbonate (CaCO ₃ ). The base reacts with hydrochloric acid (HCl) in the stomach. The reaction neutralizes the acid to relieve acid indigestion.
  ::这些抗酸药片含有碳酸碱钙酸基(CaCO3),其基底与胃中的盐酸反应。该基底与胃中的盐酸反应。该基底与盐酸反应使酸中和,以缓解酸消化。

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  Q: What products are produced when antacid tablets react with hydrochloric acid in the stomach?
  ::问题:当抗酸药片在胃部与盐酸发生反应时,会产生哪些产品?

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  A: The products are water and the salt calcium chloride (CaCl ₂ ). Carbon dioxide (CO ₂ ) is also produced. The reaction is represented by the chemical equation:
  ::A:产品为水和氯化盐(CaCl2),还产生二氧化碳(CO2)。

  CaCO ₃ + 2HCl → H ₂ O + CaCl ₂ + CO ₂

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  Summary
  ::摘要

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  • When acid and base solutions react, they produce water and a neutral ionic compound called a salt. The reaction is called a neutralization reaction.
    ::当酸和碱溶液反应时,它们产生水和中性离子化合物,称为盐。反应称为中性反应。

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  Review
  ::回顾

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  1. Describe a neutralization reaction.
     ::描述一个中和反应。
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  2. What is a salt? Give an example.
     ::盐是什么 举个例子
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  3. Fill in the missing products in the chemical equation below. It represents a neutralization reaction between solutions of nitric acid (HNO ₃ ) and potassium hydroxide (KOH): HNO ₃ + KOH → ____ + _____
     ::它代表硝酸(HNO3)和氢氧化钾(KOH):HNO3 + KOH + + + + + + 的溶液之间的中和反应。

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  Resources
  ::资源