∘ Liquid
Molecules moving freely
Molecules moving freely
🔄 Freezing
Energy released, temp constant
Energy released, temp constant
◇ Solid
Molecules locked in crystal
Molecules locked in crystal
ΔT = i × kf × m
Freezing Point Depression Equation
Time: 0s
Salt Type (Road Deicers)
Concentration
Cooling Rate
Display Options
1.86°C
ΔT (Depression)
-1.86°C
Freezing Point
2
van't Hoff (i)
1.86
kf (°C/m)
�️ What's Happening on the Road?
Rock salt (NaCl) breaks into Na⁺ and Cl⁻ ions on the road. These particles block water molecules from forming ice crystals, requiring a lower temperature to freeze. That's why roads stay clear!
💰 Road Salt Economics
Rock salt costs ~$60/ton but only works above -9°C. CaCl₂ costs ~$300/ton but works down to -29°C. Cities switch to the expensive stuff during polar vortex events!