[Neilh17]

Hi All,

I just joined this forum in the hope to attain some advice to support an ongoing project.
I am trying to find out if there are any substances that when mixed result in an instant cold reaction (0degC or below). My investigations to date led me to an ammonium nitrate/water mix. This worked pretty well, but wasn't quite cold enough for my application; plus ideally I would want a fully non-hazerdous compound. VERY Grateful for any suggestions.

Neil Salisbury UK.

[Enthalpy]

Welcome, Neilh17!

There are more compounds whose solution in water is cold, especially sugars and polyols. While these won't be more efficient than ammonium nitrate, I believe 0°C is attainable, and they are safer (even edible).

Data about salts is in the Handbook of Chemistry and Physics.

Data about glycerine, erythritol and others is on the Web, as they serve for refreshing chewing-gums. Beware glycerine can already contain a variable amount of water as-sold.

Mixing them with water isn't completely trivial because they get thick at cold, so you need to mix heartedly but still avoid bubbles if unwanted.

[Neilh17]

Thanks for the advice Enthalpy!...
Please keep it coming! If I could reach -10 Deg C I would be onto a real winner...
N