Freezing Point Depression: How Salt Melts Ice

Freezing Point Rule: Pure water freezes at 0°C (32°F), but adding salt lowers this temperature.
Salt’s Disruption: Salt ions interfere with water molecules trying to form solid ice crystals.
Melt Assist: This disruption makes ice need colder conditions to stay frozen.
Why Roads Stay Clear: Spreading salt on roads lowers the freezing point, melting ice and snow.
Brine Effect: Saltwater (brine) stays liquid below 0°C, preventing refreezing.
Energy Balance: Lowering the freezing point changes how energy moves in the water-ice mix.
Everyday Example: Salted ice is used in old-fashioned ice cream makers to keep mixtures extra cold.
Limits Exist: At extremely low temperatures, even salt can’t prevent freezing.
Different Salts: Calcium chloride and other salts work better than table salt in very cold weather.
Science in Action: Freezing point depression shows how chemistry controls winter roads and tasty treats.