Mixing distilled H20 and Prestone concentrate=heat

[DB_Cooper]

Interesting observation. When I mix distilled water with the Prestone AMAM concentrate the 50/50 gallon jugs became noticeably warmer to touch.

Using my IR temp gun..both the un-opened jugs of distilled water and the un-mixed jugs of Prestone AMAM were at 68*F. Once I mixed the H2O..the temperatures in the 50/50 went up to 80*/81*F

Obviously there is some chemical change that is happening and releasing energy.

Anyone have any clues why?

 

[Bgallagher]

the magic of dexcool

 

[NateDN10]

https://en.wikipedia.org/wiki/Enthalpy_change_of_solution

 

[DB_Cooper]

Oh, I see..an exothermic solvation process..anyone know why?

 

[kschachn]

There's no chemical change really, it is just the delta-H of mixing the solution. Most are exothermic but some are endothermic. It depends on the solute.

Delta-H

 

[expat]

Cold fusion

 

[kschachn]

Well of course the lube doesn't actually warm anything

 

[DoubleWasp]

I don't know. When I put that Kentucky Jelly on my sandwich, it warms it right up.

 

[kschachn]

Maybe Shannow can comment on hydrodynamic boundary layers and frictional heating.

 

[mjoekingz28]

Just curious as to you mixing distilled with pre-diluted. One part diluted to one part h20 would be 33:66 right?

Did it cool off to room temp or is it holding steady?

 

[Jetronic]

that would be 25:75 actually.

 

[Shannow]

Originally Posted By: kschachn
Maybe Shannow can comment on hydrodynamic boundary layers and frictional heating.


In this thread ???

OP, grab some soluble nitrate (NaOH/KOH) fertiliser, and mix it with water...goes the other way.

 

[kschachn]

Originally Posted By: Shannow
Originally Posted By: kschachn
Maybe Shannow can comment on hydrodynamic boundary layers and frictional heating.

In this thread ???

OP, grab some soluble nitrate (NaOH/KOH) fertiliser, and mix it with water...goes the other way.


Ahh noo, a failed joke. I was referring to the other... lube and heating discussion that was in this thread. Portions of which apparently got deleted making my comment out of place

 

[Brad_C]

Originally Posted By: Shannow

OP, grab some soluble nitrate (NaOH/KOH) fertiliser, and mix it with water...goes the other way.


Those two are hydroxides and they generate much heat as they dissolve. Some nitrates do as you say though. Harder to get hold of these days as they are part of that large group of chemicals with a restricted availability to save us from ourselves.

 

[DB_Cooper]

Originally Posted By: mjoekingz28
Just curious as to you mixing distilled with pre-diluted. One part diluted to one part h20 would be 33:66 right?

Did it cool off to room temp or is it holding steady?


No, I was mixing 1 part distilled H20 with 1 part Prestone AMAM concentrate to get a finished 50/50 dilution of H2O and antifreeze.

The temperature went up after mixing and returned to room temperature after about 10 minutes.

 

[Shannow]

Originally Posted By: Brad_C
Originally Posted By: Shannow

OP, grab some soluble nitrate (NaOH/KOH) fertiliser, and mix it with water...goes the other way.


Those two are hydroxides and they generate much heat as they dissolve. Some nitrates do as you say though. Harder to get hold of these days as they are part of that large group of chemicals with a restricted availability to save us from ourselves.


Bugger, I meant Nitrates, you are absolutely correct.