Sodium hydride and its reactions

Sodium hydride , also known as sodium bicarbonate, is of Na ⁺ and H ^- one ionic composition of the metal hydride is typical of salts hydride

1.

(1) Sodium hydride with a content of more than 97% is silver-white needle-like crystals, which ignite spontaneously in humid air and react explosively with water, which is much more violent than the reaction between metallic sodium and water

(2) As a strong base, sodium hydride can deprive protons (extract hydrogen) and generate hydrogen at the same time

(3) Sodium hydride will quickly absorb moisture in the air, release heat and burn

2.

(1) The countertop should be kept dry during weighing and feeding

(2) The reaction instrument must be dried in advance, and it can be weighed only when it is all ready

(3) Do not use balloons to seal the reaction system to prevent explosion

(4) If the heat release is severe, pay attention to cooling.

(5) Because the appearance of sodium hydride is mineral wax, there will be no violent reaction for a while at low temperatures, but there will often be subsequent outbreaks

(6) Because the commercially available sodium hydride is dispersed in mineral oil, if the requirements are high, ether or hydrocarbon can be used to wash off the mineral oil on the surface (if necessary, the ether or hydrocarbon can be blown dry with dry nitrogen), but the activity is greater at this time.

(7) After the completion of the reaction, before and after the quenching agent is added dropwise, a sufficient inert gas flow must be maintained over the reaction solution to dilute the generated hydrogen

(8) In case of a small fire caused by sodium hydride, dry yellow sand should be used to extinguish it

3.

Sodium hydride , lithium hydride (LiH) and potassium hydride (KH, commodity dispersion in mineral oil 35% suspension) are high chemical reactivity, it can be spontaneous exposed to air, heat or moisture, acids, The oxidant emits heat and hydrogen when it comes into contact, causing combustion and explosion

Calcium hydride (CaH ₂ ) is generally used as a desiccant in the laboratory to prepare anhydrous solvents
.
It is less active than sodium hydride, but it still has the risk of releasing hydrogen in contact with water
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Related links: Borane and the reactions involved