How do you lower the freezing point of water to -12C?
want to know how much and of what substance to add to 1 liter of water to lower it's freezing point to about -12C - ideally it would be non toxic - but preferrence is on ease to mix the substance in and cost (table salt doesn't work for my application) - the end solution must be clear. Thanks
- maussyLv 71 decade agoFavorite Answer
I would suggest you Calcium chloride
effectively CaCl2 ---> Ca++ +2Cl- (1 molecule = 3 ions)
and 1 mole of CaCl2 gives 3 osmoles
1 osmole lowers the melting point of water by 1.85°C
To lower the melting point by 12C you need = 6.48 osmoles
in molarity of CaCl2 it is equal to 6.48/3 = 2.16molar solution
A mole of CaCl2 = 40+2*35.5= 111g
this corresponds to 111*2.16 = 240g/L
- jcann17Lv 51 decade ago
Instead of using table salt, try using Magnesium Chloride, this will get you around -15 deg. C.
Check this out for a list of more common salts.Source(s): Chem Teacher