Why does nitrogen triiodide (NI3) explode: understanding explosions and the role of nitrogen

[@ChemistryTrailclasses]

When I was a student of 10 for a schools science exhibition we had made it in our school laboratory and spilled on the pavements. Explosion experienced like firing from toy gun. Thanks for remembering it and for an excellent explanation 🙏

[@pauldolinko9905]

Easy to understand and a beautiful presentation for a non-chemist. Thank you very much.

[@aldunlop4622]

Very nice, simple yet detailed explanation. very informative to a layman. It's also worth noting that explosions are dependent on the air pressure (or other medium) where they occur. They need air molecules (or rock or whatever) to push against. An explosion in space would just be the N2 molecules and wouldn't have a large shock wave as there's nothing to push and they would just disperse without much effect.

[@CrashChemistryAcademy]

Yes! Great comment, nicely explained. Thanks for posting.

[@CoffeeOMG]

My favorite chemistry teach is back! So glad to see you post again. You've been missed 😊

[@CrashChemistryAcademy]

😊 Tanks. Back in the saddle!

[@eddiestone9966]

Awesome explanation and demo video! Kudos to whoever did your hand and ear modeling!

[@CrashChemistryAcademy]

They were expensive, but I thought worth the pennies.

[@jarretberenson1214]

This was a very informative and detailed video that was nicely explained. Thank you!

[@CrashChemistryAcademy]

Thanks JB. 😊 yer the best.

[@zalqion]

Thank you so much, I understand it now

[@agnelomascarenhas8990]

What is the difference between a propellant and an explosive. is it just a rate of reaction difference, with energy release less important.

[@CrashChemistryAcademy]

Good question! A propellant can be an explosion or a controlled release of high KE gaseous molecules, depending on the application. For both energy is the most important consideration. Firearms generally use high explosives, which is the type explained in the video. Of course it would not be such an unstable compound like NI3 or unmodified nitroglycerin, but something that would need a large addition of energy to get the decomposition started. Only a tiny amount is needed to produce enough gas to propel the bullet/shell out of the barrel. Older (and some current) guns used gunpowder, whose explosion is not a decomposition, it is a burn, meaning a fast reaction with oxygen. What makes gunpowder powerful is it provides its own oxygen for the burn in very compact form in the nitrate of potassium nitrate. Out in open air gunpowder burns far slower since it is not compacted and therefore uses the far less dense oxygen from the air. A piston engine is an explosion, but like gunpowder it is a compacted burn. The piston compresses air as it moves upward in the cylinder's chamber, so the oxygen becomes more dense. The fuel injector then sprays in tiny droplets of fuel which have far greater surface area than if the gasoline were poured in as a single liquid, the greater surface area allowing for an extremely rapid burn with the compressed oxygen, releasing the high KE gases CO2 and H2O, which push down the piston. Both CO2 and H2O are low PE molecules, gasoline is high PE, and so the chemistry is similar to that of nitrogen containing explosives. Rocket propellants are not used as explosives since they require a controlled release of gas over a specified amount of time, but the idea is the same, that of a large change in PE versus KE in the reaction. Most rocket propellants however will explode if the compounds producing the reaction are too quickly exposed to each other.

[@wayneeligur7586]

I am confused - is a nuclear reaction a gas reaction then, also?

[@CrashChemistryAcademy]

The gaseous state is not relevant to nuclear reactions. A chemical reaction generally involves changes in the amount of electrons (loss or gain of electrons) or a change in the location of electrons in atoms which occurs through the interaction of atoms and molecules. The video is concerned with chemical reactions. A nuclear reaction occurs when the nuclei of two or more substances (almost always atoms or individual nuclei or protons) interact and produce nuclei that are different than the starting nuclei. For example, bombarding Li-6 atoms with H-2 atoms will result in a reaction that produces two He-4 atoms. The nuclei of He-4 are different than either of the nuclei of Li-6 or H-2.

[@wayneeligur7586]

@@CrashChemistryAcademy It brings to mind that many different states of matter that may be possible during the fission process that are so fleeting and transient. Maybe a form of this exists? During a cold fusion event, such strange elemental transitions are Routinely recorded. Don’t know if you think LENR is valid.

[@CrashChemistryAcademy]

I'm not sure states of matter are relevant in nuclear chemistry. States of matter are an emergent property of larger aggregates of particles. A single atom or molecule could not be considered to be a gas or a liquid or solid. If anything nuclear chemistry may be considered to be more in a state of plasma if anything, but I think even that is a stretch. I'm not sure what you are referring to with cold fusion regarding routinely recorded data. If cold fusion is routine, then I seem to be out to lunch.