Reaction equation between sodium hydride and carbon dioxide
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Sodium hydride fires cannot be extinguished with carbon dioxide – why is that?
It is likely that, in the presence of water, the sodium hydroxide produced reacts with CO2, releasing heat; coupled with the hydrogen gas generated, this leads to an explosive reaction, which is quite dangerous!
It is mainly a reaction with water; the first thing to keep in mind when putting out fires is that water and dry powder fire extinguishers should not be used – instead, materials such as sand or graphite should be used to cover the fire
Hazardous properties: It has high chemical reactivity and can catch fire on its own in humid air. When heated or in contact with moisture or acids, it releases heat and hydrogen, causing combustion and explosion. It can react violently with oxidizers, causing combustion or explosion. It forms hydroxides in the presence of moisture and water, and is highly corrosive. Combustion (decomposition) products: sodium oxide, water. (Note: Sodium oxide continues to react with water, and the final product is sodium hydroxide.) Chemical equations involved (step by step): 2NaH + O2 = Na2O + H2O Na2O + H2O = 2NaOH The overall chemical equation is 2NaH + O2 = 2NaOH
What I’m asking is whether it can react directly with carbon dioxide? Please listen carefully, sir!
When sodium hydride burns, it produces sodium oxide and water; ultimately, sodium hydroxide is formed: 2NaH + O2 = Na2O + H2O, and Na2O + H2O = 2NaOH. Using carbon dioxide to extinguish the fire will cause sodium hydroxide to react with carbon dioxide, and this is an exothermic reaction; the resulting increase in temperature hinders fire suppression. Sodium hydride does not react directly with carbon dioxide! The overall reaction is: 2NaH + O2 + CO2 = Na2CO3 + H2O
1# SJC1860 I don’t understand what you’re talking about
Boss, when sodium hydride reacts with water, hydrogen gas should be produced, right? It will catch fire on its own
Sodium hydride reacts with water to produce sodium hydroxide and hydrogen gas; this is an exothermic process. If heat accumulates, it can ignite the hydrogen gas. When we cleaned the packaging of sodium hydride, we found that when multiple small packages were tied together and washed with water, steam was produced, but no abnormalities occurred when each package was washed individually. The washing water was alkaline, which indicates that heat is still the underlying issue. Using a carbon dioxide fire extinguisher would cause a reaction with the liquid alkali, generating heat that could potentially ignite the hydrogen gas. Fires involving sodium hydride are usually caused by contact with water, so carbon dioxide fire extinguishers should not be used. Sodium hydride itself does not react with carbon dioxide
10# rambo1982: The analysis above is quite thorough. The question posed by the original poster seems to be why carbon dioxide fire extinguishers cannot be used to put out fires caused by sodium hydride combustion