Chemical Ice Pack/ Endothermic Quick Freeze

This demonstration mixes two solids which react endothermically, taking in enough heat to freeze a wet block of wood to the flask. The chemicals used for this reaction are barium hydroxide octahydrate [Ba(OH)2 8H2O] and ammonium nitrate [(NH4)(NO3)] , and when they react they take in heat energy (which is what freezes the water) and form water and dissolve each other.

Category:

Science & Technology

Tags:

• chem
• chemistry
• demo
• demonstration
• russia
• sully
• endothermic
• endo
• barium
• hydroxide
• Ba
• OH
• octahydrate
• H2O
• ammonium
• nitrate
• NH4
• NO3
• chemical
• ice
• pack
• quick
• freeze
• flask

[oxsweety18xo]

if you put water in the beaker from the start would the reaction be any different

[mrericsully]

@oxsweety18xo If I put water in the flask the reaction would seem less endothermic because it would also have to cool the water and if might not get cold enough to freeze the wood disk to the flask. Beyond that the reaction should still occur, but more of the ammonia gas that is released would dissolve in the extra water forming basic ammonium hydroxide. Also, it would ruin the fun of the rare/uncommon solid-solid reaction.

[esteinapt9]

are there two chemicals you could use that would produce a similar effect that could be placed on the skin?

[mrericsully]

@esteinapt9 If you are talking about just cooling the skin [like a chemical ice/cold pack] yes- in fact this reaction is used in some, but because of the toxicity of the Ba(OH)2 many times the (NH4)Cl and H2O are used [it has an endothermic heat of solution].

If you are talking about freezing that skin that is unsafe and could cause frostbite and although I know ways I wouldn't try them.

If you are talking about direct application to the skin it would be doable, but is easier to make a pack.

[mrericsully]

@shahidfurqan2003 Ammonium nitrate is somewhat easy to obtain although its purity might be questionable from some sources. Barium hydroxide on the other hand is not readily available.

[shahidfurqan2003]

@heavnly 98 bro tell simly way which chemical used and, is is it available every ware in market. where is other usage of these chemical's

[mrtarpon]

Oh my god would the students shut up.

[MrKicks2010]

bet this is highschool lol kids are so damn rude...

[darkstar3472]

Shhhhhhhh

[mrericsully]

@heavenly98 I'm not at school right now and so I don't recall which is which, but I use 16-18 grams of one and 32 of the other. You cold probably work it out with stoichiometry, or wait until I"m back at school and I will try to look it up.