CALCIUM HYDRIDE

CALCIUM HYDRIDE - Names and Identifiers

Name	Calcium hydride
Synonyms	CaH2 Cakium hydride Calcium hydride CALCIUM HYDRIDE calcium dihydride Calcium hydride (CaH2) Calcium hydride [UN1404] [Dangerous when wet]
CAS	7789-78-8 125544-53-8
EINECS	232-189-2
InChI	InChI=1/Ca.2H/rCaH2/h1H2
InChIKey	FAQLAUHZSGTTLN-UHFFFAOYSA-N

CALCIUM HYDRIDE - Physico-chemical Properties

Molecular Formula	CaH2
Molar Mass	42.09
Density	1.9
Melting Point	816 °C (lit.)
Water Solubility	Soluble in water and alcohol. Insoluble in benzene.
Appearance	powder
Specific Gravity	1.9
Color	Light gray
Merck	14,1672
Storage Condition	Store below +30°C.
Stability	Stable, but reacts violently with water, liberating and igniting hydrogen. Contact with strong oxidizers may cause fire or explosion. Incompatible with strong oxidizing agents, strong acids, halogens,
Sensitive	Moisture Sensitive
Physical and Chemical Properties	Calcium hydride has strong reducibility. It is often used as a strong reducing agent and is used to produce hydrogen in field work. Calcium can be prepared by heating the calcium in a stream of hydrogen.
Use	Used as reducing agent and condensing agent in organic synthesis, as desiccant and hydrogen production material

CALCIUM HYDRIDE - Risk and Safety

Hazard Symbols	F - Flammable
Risk Codes	15 - Contact with water liberates extremely flammable gases
Safety Description	S24/25 - Avoid contact with skin and eyes. S43 - In case of fire use ... (there follows the type of fire-fighting equipment to be used.) S7/8 - S43A -
UN IDs	UN 1404 4.3/PG 1
WGK Germany	1
TSCA	Yes
HS Code	28500090
Hazard Class	4.3
Packing Group	I

CALCIUM HYDRIDE - Nature

Open Data Verified Data

colorless orthorhombic crystal; Industrial products are gray, orthogonal crystal or powder. Sensitive to moisture. The relative density was 1. 70. Melting point 816 °c (in hydrogen). Ca and H2 are decomposed at 600 °c. It does not react with dry air, nitrogen and chlorine at normal temperature, but can react with the above gases at high temperature to generate calcium oxide, calcium carbide and calcium chloride respectively. It can also react with ethanol to produce hydrogen and ethanol calcium when it is decomposed in water. The reduction of metal oxides is more intense than sodium hydride or lithium hydride.

Last Update：2024-01-02 23:10:35

CALCIUM HYDRIDE - Preparation Method

Open Data Verified Data

purity about 99. 5% refined calcium is placed in the iron plate and placed in the center of the quartz reaction tube. The inlet pipe and the outlet pipe are respectively installed with rubber plugs at both ends of the quartz reaction tube, and purified hydrogen is passed through the inlet pipe, the outlet tube was connected to the fume hood via a mineral oil bubbler. The reaction tube was heated with an electric furnace. The purified hydrogen gas is introduced into a large amount of hydrogen gas to replace the air in the reaction system at the beginning, and then heated in an electric furnace. The reaction starts at about 200 ℃ and is further heated to 250~300 ℃, the reaction was carried out by introducing hydrogen gas at a flow rate of 0.6mL/min, and the reaction was completed by about 2H. The calcium hydride produced was porous off-white crystalline powder, and the purity of the calcium hydride was about 99%.

Last Update：2022-01-01 11:07:09

CALCIUM HYDRIDE - Use

Open Data Verified Data

for powder metallurgy, when heated to 600 to 1000 ° C., it can be reduced with metal oxides such as zirconium, niobium and hafnium to obtain corresponding metal powders. It can be used as a portable hydrogen generating agent, and can also be used as a reducing agent, a desiccant, and an analytical reagent.

Last Update：2022-01-01 11:07:08

CALCIUM HYDRIDE - Safety

Open Data Verified Data

chemical reactivity is very high, in case of moisture, water or acid reaction, release hydrogen and can cause combustion. With the oxidant, metal oxide reaction. In the event of moisture and moisture to generate hydroxide, strong corrosion. Glass bottle packaging, each bottle of net weight 500g, and then concentrated in the wood box lining material, or with metal drum liner polyethylene bag hermetic sealing, net weight of each barrel 25kg. "Moisture-proof" and "flammable" signs shall be displayed on the package. Hazard code: flammable item in wet condition. GB 4.3 class 43020. UN N0.14040 IMDG CODE P. 4337, category 1. Toxicity and protection: This product has strong irritation to mucous membrane, upper respiratory tract, eyes and skin. After inhalation, may be due to laryngeal and bronchial spasm, inflammation, edema, chemical Pneumonia or pulmonary edema and death. After contact cause burning sensation, Cough, wheezing, laryngitis, shortness of breath, Head Pain, Nausea, Vomit, etc. Dust on the eyes, nose, skin and respiratory system has a strong stimulating effect, in the event of moisture or moisture generated by the strong corrosive calcium hydroxide. When possible exposure to poisons, should wear a hood type electric air supply filter dust respirator. When necessary, it is recommended to wear a self-contained respirator; Wear chemical protective clothing, wear rubber gloves I Smoking is strictly prohibited at work site; Pay attention to personal hygiene. Skin contact: remove contaminated clothing immediately and rinse with plenty of running water for at least 15 minutes. The patient visited hospital. Eye contact: lift the eyelids immediately and rinse thoroughly with plenty of running water or saline for at least 15 minutes. The patient visited hospital. Inhalation: rapid departure from the scene to fresh air. Keep airway unobstructed. Such as Dyspnea, to the delivery of oxygen. If breathing stops, perform artificial respiration immediately. The patient visited hospital. Ingestion: the wrong people with water gargle, to drink milk or egg white. The patient visited hospital. Fire extinguishing method: Do not use water, foam, carbon dioxide, halogenated hydrocarbons (such as 1211 extinguishing agent) and other fire extinguishing. Can only be used metal cover or dry graphite, dry dolomite powder in the end of the fire.

Last Update：2022-01-01 11:07:10

CALCIUM HYDRIDE - Reference Information

NIST chemical information	information provided by: webbook.nist.gov (external link)
EPA chemical substance information	information provided by: ofmpeb.epa.gov (external link)
Introduction	calcium hydride is usually prepared from purified calcium with a purity of 99.5% by reacting with purified hydrogen at high temperature, it does not react with dry air, nitrogen and chlorine at room temperature. Water decomposition is a material that can release a large amount of high purity hydrogen. Calcium hydride can be used as a portable hydrogen generator, when applied to field work, it can provide efficient energy, and the release of hydrogen negative ions has human health care function.
alkaline earth metal	calcium hydride is an alkaline earth metal that is not as stable as lithium hydride but is more stable than other alkali metal salts of hydrogenation. Chemical formula cah2. Molecular weight 42.10. White monoclinic crystals or lumps. Industrial products are gray in color. The effect of moist humidified air releases hydrogen to leave behind calcium hydroxide. The specific gravity was 1.9. Decomposition at about 600 °c. Melting point 816 °c (in hydrogen). When water, carboxylic acid, low carbon alcohol decomposition to generate hydrogen. Decomposition began at 600 °c. It does not react with dry oxygen, nitrogen and chlorine at room temperature, but can react at high temperature to generate CaO, Ca3N2 and CaCl2 respectively. It reacts with water at room temperature to produce calcium hydroxide and hydrogen. calcium hydride has strong reducibility, which can free metal oxides and chlorides, for example, 2CaH2 MO2 → 2CaO 2H2 M (metal). Calcium hydride is often used as a strong reducing agent and in the field to produce hydrogen. preparation method: Calcium metal is put into an iron pan, heated to about 300 °c by electric heating or oil, and reacted with hydrogen to prepare calcium hydride. Ca H2 → CaH2 214kJ · mol-1 calcium oxide can also be prepared by reducing calcium oxide with magnesium in a hydrogen stream, and a high-purity calcium hydride product cannot be obtained due to difficulties in separating calcium oxide. CaO Mg H2 → CaH2 MgO Application: The oxides of zirconium, niobium, uranium and chromium can be reduced by heating to 600~1000 ℃, powders of these metals are produced, so that calcium hydride can be used in powder metallurgy. Insoluble in ether, can react with ethanol, hydrogen and ethanol calcium. Hydrogen can be produced by reaction with water, and one gram of this product can release one liter of hydrogen in water, so it is often used as a portable hydrogen source. In addition, calcium hydride is also used as a dehydration, hydrogenation, condensation agent of organic compounds; Or as a drying agent, its drying effect is better than sodium, phosphorus pentoxide.
quenching method	post-treatment is that if the amount is not large, it can be directly quenched with water. If the amount is large, water is slowly added dropwise. This was suspended in dry tetrahydrofuran and ethanol or isopropanol was added slowly with stirring until no more hydrogen was evolved and the mixture was clear.
toxicity	in case of moisture, water or acid reaction, release hydrogen and can cause combustion, and oxidant, the metal oxide reacts vigorously. Dust on the eyes, nose, skin and respiratory system has a strong stimulating effect, in the event of moisture or moisture generated by the strong corrosive calcium hydroxide. See lithium hydride for others.
Use	hydrogen generating agent, reducing agent, desiccant, analytical reagent. used as reducing agent and condensing agent in organic synthesis, as desiccant and hydrogen production material used as reducing agent and condensing agent in organic synthesis, also used as desiccant and hydrogen production materials used as analytical reagent, reducing agent and desiccant, also used as raw materials for hydrogen production used as reducing agent, desiccant, chemical analysis reagent, etc. used as a reducing agent to reduce rare metal oxides to produce rare metals, liquid and gas desiccants, chemical analysis reagents, etc. Organic Synthesis.
production method	the purified calcium with a purity of about 99.5% is placed in an iron plate in the center of a quartz reaction tube, the inlet pipe and the outlet pipe are respectively installed with rubber plugs at both ends of the quartz reaction tube, and hydrogen gas is purified from the inlet pipe. The outlet pipe is connected to the ventilated kitchen through a mineral oil bubbler. The reaction tube was heated with an electric furnace. The purified hydrogen is initially replaced by a large amount of hydrogen to remove the air from the reaction system, and then heated in an electric furnace. The reaction starts at about 200 ℃ and is further heated to 250~300 ℃, the reaction was carried out by introducing hydrogen gas at a flow rate of 0.6 mL/min, and the reaction was completed by about 2H. The calcium hydride produced was porous off-white crystalline powder, and the purity of the calcium hydride was about 99%. Its Ca + H2 → CaH2
category	explosive substance
explosive hazard characteristics	reaction with tetrahydrofuran heating explosion; Mixed with potassium chlorate, hypochlorite, bromate, perchlorate thermally sensitive, friction-sensitive explosion
storage and transportation characteristics	warehouse is ventilated and dried at low temperature; Anti-shock, moisture-proof, high temperature-proof
fire extinguishing agent	foam, carbon dioxide, dry powder
toxic substance data	information provided by: pubchem.ncbi.nlm.nih.gov (external link)