Calcium hydride: Difference between revisions

Latest revision as of 05:45, 16 February 2025

Calcium Hydride[edit]

Calcium hydride is an inorganic compound with the chemical formula CaH_. It is a gray powder that reacts vigorously with water, releasing hydrogen gas. Calcium hydride is used as a drying agent and as a reducing agent in various chemical reactions.

Chemical Properties[edit]

Calcium hydride is a salt-like hydride, composed of calcium and hydrogen. It is a powerful reducing agent and reacts with water to produce calcium hydroxide and hydrogen gas. The reaction can be represented by the following equation:

CaH_ + 2 H_O _ Ca(OH)_ + 2 H__

This property makes calcium hydride useful in generating hydrogen gas in laboratory settings.

Preparation[edit]

Calcium hydride can be prepared by the direct combination of calcium and hydrogen at elevated temperatures. The reaction is as follows:

Ca + H_ _ CaH_

This synthesis requires high temperatures and is typically carried out in an inert atmosphere to prevent the formation of calcium oxide.

Applications[edit]

Calcium hydride is primarily used as a desiccant for drying solvents and gases. It is also employed in the production of hydrogen gas and as a reducing agent in the synthesis of various organic and inorganic compounds.

Drying Agent[edit]

Due to its ability to react with water, calcium hydride is used to dry solvents and gases. It is particularly useful in situations where traditional drying agents, such as molecular sieves, are ineffective.

Hydrogen Generation[edit]

Calcium hydride is used in portable hydrogen generators. When mixed with water, it releases hydrogen gas, which can be used as a fuel or in chemical reactions.

Reducing Agent[edit]

In organic synthesis, calcium hydride is used to reduce carbonyl compounds to alcohols. It is also used in the reduction of metal oxides to their corresponding metals.

Safety[edit]

Calcium hydride is a reactive compound and should be handled with care. It reacts violently with water and acids, releasing flammable hydrogen gas. Proper safety precautions, including the use of gloves and eye protection, should be observed when handling this compound.

Related pages[edit]

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-'''Calcium Hydride''' is a chemical compound with the formula [[CaH2]]. This grey powder (white when pure), which is a [[hard metal]], is used as a drying agent for a wide range of solvents. It is also used in laboratories to produce [[hydrogen]] gas.
+{{DISPLAYTITLE:Calcium Hydride}}
+==Calcium Hydride==
+[[File:Calcium_Hydride_(CaH2).jpg|thumb|right|Calcium hydride powder]]
+'''Calcium hydride''' is an inorganic compound with the chemical formula CaH_. It is a gray powder that reacts vigorously with water, releasing hydrogen gas. Calcium hydride is used as a drying agent and as a reducing agent in various chemical reactions.
 ==Chemical Properties==
-Calcium hydride is a [[binary compound]] of [[calcium]] and [[hydrogen]]. It is a grey or white powder when pure, with a high melting point of 816°C. It is a [[salt]] (ionic compound), being made up of calcium ions (Ca2+) and hydride ions (H−). The compound is thus an [[alkaline earth hydride]]. It reacts vigorously with water to form calcium hydroxide and hydrogen gas.
+Calcium hydride is a [[salt]]-like [[hydride]], composed of [[calcium]] and [[hydrogen]]. It is a powerful [[reducing agent]] and reacts with water to produce [[calcium hydroxide]] and [[hydrogen gas]]. The reaction can be represented by the following equation:
+: CaH_ + 2 H_O _ Ca(OH)_ + 2 H__
+This property makes calcium hydride useful in generating hydrogen gas in laboratory settings.
+==Preparation==
+Calcium hydride can be prepared by the direct combination of [[calcium]] and [[hydrogen]] at elevated temperatures. The reaction is as follows:
+: Ca + H_ _ CaH_
+This synthesis requires high temperatures and is typically carried out in an inert atmosphere to prevent the formation of [[calcium oxide]].
-==Production==
+==Applications==
-Calcium hydride is produced industrially by heating [[lime]] (calcium oxide) with [[hydrogen]] in a high temperature [[furnace]]. The reaction is as follows:
+Calcium hydride is primarily used as a [[desiccant]] for drying solvents and gases. It is also employed in the production of [[hydrogen]] gas and as a reducing agent in the synthesis of various organic and inorganic compounds.
-CaO + H2 → CaH2 + H2O
+===Drying Agent===
+Due to its ability to react with water, calcium hydride is used to dry [[solvents]] and [[gases]]. It is particularly useful in situations where traditional drying agents, such as [[molecular sieves]], are ineffective.
-The compound can also be produced by direct combination of calcium and hydrogen at temperatures between 300-400°C.
+===Hydrogen Generation===
+Calcium hydride is used in portable hydrogen generators. When mixed with water, it releases hydrogen gas, which can be used as a fuel or in [[chemical reactions]].
-==Uses==
+===Reducing Agent===
-The main use of calcium hydride is as a drying agent in the preparation of certain [[solvent]]s, such as [[ether]] and [[tetrahydrofuran]]. It can also be used to dry the air in a gas line to prevent condensation and the resulting corrosion. In laboratories, it is commonly used to produce small quantities of extremely pure hydrogen gas.
+In organic synthesis, calcium hydride is used to reduce [[carbonyl]] compounds to [[alcohols]]. It is also used in the reduction of [[metal oxides]] to their corresponding metals.
 ==Safety==
-Calcium hydride is a highly reactive compound and should be handled with care. It reacts violently with water, releasing large amounts of heat and hydrogen gas, which can cause a fire or explosion. It should be stored in a cool, dry place, away from sources of moisture.
+Calcium hydride is a reactive compound and should be handled with care. It reacts violently with water and acids, releasing flammable hydrogen gas. Proper safety precautions, including the use of [[gloves]] and [[eye protection]], should be observed when handling this compound.
-==See Also==
+==Related pages==
-* [[Hydride]]
 * [[Calcium]]
 * [[Hydrogen]]
+* [[Reducing agent]]
+* [[Desiccant]]
-[[Category:Chemical compounds]]
 [[Category:Calcium compounds]]
 [[Category:Hydrides]]
-{{Chem-stub}}
+[[Category:Reducing agents]]
-{{No image}}