What am I missing? I cannot reconcile the difference between what the internet says the freezing point of CaCl2 is vs the calculation, which means my calculation must be off, but I am not sure how.
- A Solute of 1700g of CaCl2 would equate to ~15.32 Moles @ 110.98 Atomic Mass.
- Mix in 1 Gallon of water, or 3.785 kg.
- This represents a ~31% solution (1700/(1700+3785))
- Molality would be 4.047 (15.32 / 3.875)
- With a Van't Hoff of 3...
- The Freezing Point Depression would be -22.52C (3*1.855*4.047)
I think all of that is right, but when I look at the tables online they show that a 31% CaCl2 solution would have a freezing point of ~-34C - ~-37C
These sites shows a 30% concentration to have a freezing point of ~-46.1C: