exothermic, endothermic and their surroundings.

[coletted]

Hi, I'm new to this site and was wondering if anyone can help me on an assignment. My assignment is about food heating packs. What happens to the surroundings in an exothermic heat pack, its energy changes, the chemicals in the heat packs the bonding breaking and making, oh and the word equations. I can't seem to find any of these things to research on the internet. So I'm hoping there's someone on here that can help me, because I'm at desperate point now.

Thanks for reading xx

[MonDie]

If I recall, endo/exothermic pertains to whether the reaction absorbs or releases heat.

[Endy0816]

http://en.wikipedia.org/wiki/Flameless_ration_heater

 

Should be what you are looking for.

[fiveworlds]

What happens to the surroundings in an exothermic heat pack

 

 

endothermic - reaction absorbs heat from surroundings

exothermic - reaction gives out heat to surroundings

 

its energy changes

 

Depends on the chemicals used some reactions are far more exothermic than others explosives for example.

 

 

the chemicals in the heat packs the bonding breaking and making

 

 

Depend on the manufacturer. I would assume they would need to be exothermic enough to heat the food to appropriate levels. There is also endothermic heat packs used for sports injuries and cooling down foods when going camping. Usually but not always the pack is divided into a number of sections one of which contains water when the pack is cracked the water mixes with the substance and starts the chemical reaction.

Edited December 31, 2014 by fiveworlds

[studiot]

 

Fiveworlds

 

endothermic - reaction absorbs heat from surroundings

exothermic - reaction gives out heat to surroundings

 

Yes this is correct, but it is worth emphasising that the terms apply only to heat energy.

 

@colleted - Welcome

 

So if you have heard of the Law of Conservation of Energy (also called the First Law of Thermodynamics) please note that there are other forms of energy where the transfer may be in another direction.