Endothermic reaction when mixing macros

Zorfox · 02-10-2013, 10:24 PM

I had to mix up some dry ferts today. I used different bottles that were thinner than what I had before. I added 5tbsp. of KNO3, 1 1/4 tbsp. of KH2PO4, 20ml Excel (mistakenly) and 300cc of water. When I shook the bottles to mix, it became quite cold ; 53F from 74F in fact. I never noticed this before (thicker bottles I guess). Is this caused by mixing the KNO3 with water or what? I know cold packs mix ammonium nitrate, potassium hydroxide and water which produces KNO3 and ammonia gas but not sure if it works the other way around. Just curious.

**Jeffww** · 02-10-2013, 10:25 PM

Yah, most of these salts absorb quite a bit of hit when mixed. Although some make things warmer. I think CaCl2's dissociation is quite exothermic.

homemadepopcorn · 02-10-2013, 10:35 PM

It depends on how the species is solvated and yes, CaCl2 is exothermic.

02-10-2013, 10:24 PM	#1
Zorfox Planted Tank Obsessed (View User Tanks) PTrader: (4/100%) Join Date: Jun 2012 Location: Jacksonville, FL Posts: 431	Endothermic reaction when mixing macros I had to mix up some dry ferts today. I used different bottles that were thinner than what I had before. I added 5tbsp. of KNO3, 1 1/4 tbsp. of KH2PO4, 20ml Excel (mistakenly) and 300cc of water. When I shook the bottles to mix, it became quite cold ; 53F from 74F in fact. I never noticed this before (thicker bottles I guess). Is this caused by mixing the KNO3 with water or what? I know cold packs mix ammonium nitrate, potassium hydroxide and water which produces KNO3 and ammonia gas but not sure if it works the other way around. Just curious.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

02-10-2013, 10:25 PM	#2
Jeffww Microsynodontis Lover (View User Tanks) PTrader: (9/100%) Join Date: Aug 2010 Location: Houston Posts: 2,081	Yah, most of these salts absorb quite a bit of hit when mixed. Although some make things warmer. I think CaCl2's dissociation is quite exothermic.

02-10-2013, 10:35 PM	#3
homemadepopcorn Planted Tank Obsessed (View User Tanks) PTrader: (16/100%) Join Date: Mar 2012 Location: New York City, NY Posts: 350	It depends on how the species is solvated and yes, CaCl2 is exothermic.