So in science we are doing cold packs,

Question

So we have to use water and the following....
Please help me choose one(have to get from 0 degrees to 5 degrees no higher no less or you will fail)
1. Urea
2. Potassium Chloride
3. Ammonium Chloride
4. Sodium Chloride

Answer 1

http://webserver.dmt.upm.es/~isidoro/dat1/Heat%20of%20solution%20data.pdf

I am puzzled: you mentioned "cold packs", which absorb heat going into solution, which would indicate going from 5 deg to 0 deg.

Answer 2

I'm not sure I understand your question but if you have heard of hot packets(a packet you shake and gets warm) It's like that but the object of the investigation is to make it cold not warm. Sorry if it dosen't answer your confusion