Using probably more than 10mL of water and as much ice as I need, how can I achieve the lowest temperature possible if I'm allowed to use (at most 20g) of any one substance?
for example: using 10mL of water, a ton of ice, and Sodium Chloride(salt) The temperature yields about -15 degrees Celsius.
I think because NaCl is ionic and thus has a stronger electronegativity it sticks to the H2O molecules causing them to melt?
What would be the best substance to use for reaching the lowest temp?
Magnesium sulfate (hepta/hexa/etc..)hydrate
or
Magnesium carbonate
or
glycerol (I'm guessing this is a bad choice because its a mostly non-polar substance)