<p><b>氨水</b>指氨氣的水溶液，可寫作<span><span><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\ce {NH3}}}">
  <semantics>
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            <mrow class="MJX-TeXAtom-ORD">
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    <annotation encoding="application/x-tex">{\displaystyle {\ce {NH3}}}</annotation>
  </semantics></math></span></span>(aq)。有強烈刺鼻氣味，為具弱鹼性的液體。氨水中，氨氣分子發生微弱水解生成氫氧根離子及銨根離子，舊式化學書本中常記作「<span><span><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\ce {NH4OH}}}">
  <semantics>
    <mrow class="MJX-TeXAtom-ORD">
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        <mrow class="MJX-TeXAtom-ORD">
          <msubsup>
            <mtext>NH</mtext>
            <mrow class="MJX-TeXAtom-ORD">
              <mn>4</mn>
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            <mrow class="MJX-TeXAtom-ORD">
              <mspace width="0pt" height="0pt" depth=".2em"></mspace>
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          <mtext>OH</mtext>
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    <annotation encoding="application/x-tex">{\displaystyle {\ce {NH4OH}}}</annotation>
  </semantics></math></span></span>」或「<span><span><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\ce {NH3.H2O}}}">
  <semantics>
    <mrow class="MJX-TeXAtom-ORD">
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        <mrow class="MJX-TeXAtom-ORD">
          <msubsup>
            <mtext>NH</mtext>
            <mrow class="MJX-TeXAtom-ORD">
              <mn>3</mn>
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            <mrow class="MJX-TeXAtom-ORD">
              <mspace width="0pt" height="0pt" depth=".2em"></mspace>
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          </msubsup>
          <mo>⋅<!-- ⋅ --></mo>
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            <mtext>H</mtext>
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          <mtext>O</mtext>
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    <annotation encoding="application/x-tex">{\displaystyle {\ce {NH3.H2O}}}</annotation>
  </semantics></math></span></span>」，但「氫氧化銨」事實上並不存在，只是對氨水溶液中的離子的描述，並無法從溶液中分離出來。
</p><p>氨的在水中的電離可以表示為：
</p>
<dl><dd><span><span><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\ce {NH3*H2O &lt;&lt;=&gt; {NH4}^{+}+ OH-}}}">
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        <mrow class="MJX-TeXAtom-ORD">
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            <mtext>NH</mtext>
            <mrow class="MJX-TeXAtom-ORD">
              <mn>3</mn>
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            <mrow class="MJX-TeXAtom-ORD">
              <mspace width="0pt" height="0pt" depth=".2em"></mspace>
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          <mo>⋅<!-- ⋅ --></mo>
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            <mtext>H</mtext>
            <mrow class="MJX-TeXAtom-ORD">
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          <mtext>O</mtext>
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                <mtext>NH</mtext>
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          <mo>+</mo>
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            <mtext>OH</mtext>
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    <annotation encoding="application/x-tex">{\displaystyle {\ce {NH3*H2O &lt;&lt;=&gt; {NH4}^{+}+ OH-}}}</annotation>
  </semantics></math></span></span></dd></dl><p>反應平衡常數<span><span><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle K_{b}=1.8\times 10^{-5}}">
  <semantics>
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    <annotation encoding="application/x-tex">{\displaystyle K_{b}=1.8\times 10^{-5}}</annotation>
  </semantics></math></span></span>。
</p><p><span><span><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \mathrm {K_{b}={[NH_{4}^{+}][OH^{-}] \over [NH_{3}]}} }">
  <semantics>
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              <mi mathvariant="normal">b</mi>
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          <mo>=</mo>
          <mrow class="MJX-TeXAtom-ORD">
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    <annotation encoding="application/x-tex">{\displaystyle \mathrm {K_{b}={[NH_{4}^{+}][OH^{-}] \over [NH_{3}]}} }</annotation>
  </semantics></math></span></span>
</p><p>1M氨水的pH值為11.63，大約有0.42%的<span><span><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\ce {NH3}}}">
  <semantics>
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        <mrow class="MJX-TeXAtom-ORD">
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            <mtext>NH</mtext>
            <mrow class="MJX-TeXAtom-ORD">
              <mn>3</mn>
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            <mrow class="MJX-TeXAtom-ORD">
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    <annotation encoding="application/x-tex">{\displaystyle {\ce {NH3}}}</annotation>
  </semantics></math></span></span>變為<span><span><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\ce {NH4{^{+}}}}}">
  <semantics>
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            <mtext>NH</mtext>
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              <mn>4</mn>
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    <annotation encoding="application/x-tex">{\displaystyle {\ce {NH4{^{+}}}}}</annotation>
  </semantics></math></span></span>。
</p><p>氨水是實驗室中氨的常用來源。它可與含銅(II)離子的溶液作用生成深藍色的配合物，也可用於配置銀氨溶液等分析化學試劑。
</p>


<h2><span id=".E7.94.A8.E9.80.94"></span><span id="用途">用途</span></h2>
<p>氨水可被土中的土壤膠體吸附和被作物吸收，無殘留物質，適用於各種土壤和作物。氨水也可以作為玻璃的清潔劑。
</p>
<h2><span id=".E5.8F.82.E8.A7.81"></span><span id="参见">參見</span></h2>
<ul><li>氨 - 液氨</li></ul><ul><li>共軛酸</li></ul><h2><span id=".E5.8F.83.E8.80.83.E8.B3.87.E6.96.99"></span><span id="參考資料">參考資料</span></h2>
<h2><span id=".E5.A4.96.E9.83.A8.E9.93.BE.E6.8E.A5"></span><span id="外部链接">外部連結</span></h2>
<ul><li>氨水的物理性質</li></ul><!-- 
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**氨水**指氨氣的水溶液，可寫作 ${\ce {NH3}}$ (aq)。有強烈刺鼻氣味，為具弱鹼性的液體。氨水中，氨氣分子發生微弱水解生成氫氧根離子及銨根離子，舊式化學書本中常記作「 ${\ce {NH4OH}}$ 」或「 ${\ce {NH3.H2O}}$ 」，但「氫氧化銨」事實上並不存在，只是對氨水溶液中的離子的描述，並無法從溶液中分離出來。

氨的在水中的電離可以表示為：

　
: ${\ce {NH3*H2O <<=> {NH4}^{+}+ OH-}}$

反應平衡常數 $K_{b}=1.8\times 10^{-5}$ 。

$$
\mathrm {K_{b}={[NH_{4}^{+}][OH^{-}] \over [NH_{3}]}}
$$

1M 氨水的 pH 值為 11.63，大約有 0.42% 的 ${\ce {NH3}}$ 變為 ${\ce {NH4{^{+}}}}$ 。

氨水是實驗室中氨的常用來源。它可與含銅 (II) 離子的溶液作用生成深藍色的配合物，也可用於配置銀氨溶液等分析化學試劑。

## 用途

氨水可被土中的土壤膠體吸附和被作物吸收，無殘留物質，適用於各種土壤和作物。氨水也可以作為玻璃的清潔劑。

## 參見

* 氨 - 液氨
* 共軛酸

## 參考資料

## 外部連結

* 氨水的物理性質
1336-21-6