<p><b>五氧化二鈮</b>是鈮的氧化物之一，化學式為Nb<sub>2</sub>O<sub>5</sub>。
</p>


<h2><span id=".E6.80.A7.E8.B4.A8"></span><span id="性质">性質</span></h2>
<p>白色粉末。不溶於水，難溶於酸，可溶於熔融硫酸氫鉀或鹼金屬碳酸鹽和氫氧化物中。
</p>
<h2><span id=".E5.88.B6.E5.A4.87"></span><span id="制备">製備</span></h2>
<p>鈮用硝酸和氫氟酸混酸溶解得氟鈮酸，經萃取鈮和反萃後，將氟鈮酸與氨水作用，沉澱出氫氧化鈮。氫氧化鈮經洗滌、烘乾和灼燒，得五氧化二鈮。
</p>
<dl><dd><span><span><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ 3Nb+5HNO_{3}+21HF\rightarrow 3H_{2}NbF_{7}+5NO+10H_{2}O}">
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    <annotation encoding="application/x-tex">{\displaystyle \ 3Nb+5HNO_{3}+21HF\rightarrow 3H_{2}NbF_{7}+5NO+10H_{2}O}</annotation>
  </semantics></math></span></span></dd>
<dd><span><span><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ H_{2}NbF_{7}+7NH_{3}\cdot H_{2}O\rightarrow Nb(OH)_{5}\downarrow +7NH_{4}F+2H_{2}O}">
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    <annotation encoding="application/x-tex">{\displaystyle \ H_{2}NbF_{7}+7NH_{3}\cdot H_{2}O\rightarrow Nb(OH)_{5}\downarrow +7NH_{4}F+2H_{2}O}</annotation>
  </semantics></math></span></span></dd>
<dd><span><span><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ 2Nb(OH)_{5}\rightarrow Nb_{2}O_{5}+5H_{2}O}">
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    <annotation encoding="application/x-tex">{\displaystyle \ 2Nb(OH)_{5}\rightarrow Nb_{2}O_{5}+5H_{2}O}</annotation>
  </semantics></math></span></span></dd></dl><h2><span id=".E7.94.A8.E9.80.94"></span><span id="用途">用途</span></h2>
<p>用作拉鈮酸鎳單晶、催化劑、耐火材料。也用於生產製取鈮及其他鈮化合物、鈮鐵和鈮合金。
</p>
<h2><span id=".E5.8F.82.E8.80.83.E6.96.87.E7.8C.AE"></span><span id="参考文献">參考文獻</span></h2>

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**五氧化二鈮**是鈮的氧化物之一，化學式為 Nb2O5。

## 性質

白色粉末。不溶於水，難溶於酸，可溶於熔融硫酸氫鉀或鹼金屬碳酸鹽和氫氧化物中。

## 製備

鈮用硝酸和氫氟酸混酸溶解得氟鈮酸，經萃取鈮和反萃後，將氟鈮酸與氨水作用，沉澱出氫氧化鈮。氫氧化鈮經洗滌、烘乾和灼燒，得五氧化二鈮。

　
: $\ 3Nb+5HNO_{3}+21HF\rightarrow 3H_{2}NbF_{7}+5NO+10H_{2}O$

　
: $\ H_{2}NbF_{7}+7NH_{3}\cdot H_{2}O\rightarrow Nb(OH)_{5}\downarrow +7NH_{4}F+2H_{2}O$

　
: $\ 2Nb(OH)_{5}\rightarrow Nb_{2}O_{5}+5H_{2}O$

## 用途

用作拉鈮酸鎳單晶、催化劑、耐火材料。也用於生產製取鈮及其他鈮化合物、鈮鐵和鈮合金。

## 參考文獻
1313-96-8