If we use salt to melt ice outside, why do we use salt to freeze ice cream when we make it?

In middle school science classes, we learn that water (H2O) is a solvent, and salt is NaCl. When the water dissolves the salt it changes the chemical make-up of the solution wich changes the properties of the solution. Adding salt to water lowers the point at wich it freezes. And out on the street, it essentially does the same thing. the salt lowers the temperature at which the water freezes. So the freezing point is 32 degrees, and it is 28 degrees outside, and I put salt down on my sidewalk, the salt begins to be disolved by the water, which in turns lowers the point that the water containg the salt solution freezes, and melts the water away.


Any way, the salt water solution in icecream making is a bath where the liquid ice cream is set in, the water solution has the ability to be super chilled and causes the ice cream to freeze, wow this ended up being rather wordyIf we use salt to melt ice outside, why do we use salt to freeze ice cream when we make it?
They are two different salts





When you use salt for ice cream you cool the mixture back down to below a melting temperature. Salt will not work well on a sidewalk or road in constant freezing temperatures





The salt used to melt ice on roads and sidewalks has other chemicals in it.


Chemicals used to melt ice:


*Ammonium sulfate (NH4)2SO4 -7掳C (20掳F)


*Calcium chloride CaCl2 -29掳C (-20掳F) Melts ice faster than sodium chloride Attracts moisture, surfaces slippery below -18掳C (0掳F)


*Calcium magnesium acetate (CMA) Calcium carbonate CaCO3, magnesium carbonate MgCO3, and acetic acid CH3COOH -9掳C (15掳F) Safest for concrete %26amp; vegetation Works better to prevent re-icing than as ice remover


*Magnesium chloride MgCl2 -15掳C (5掳F) Melts ice faster than sodium chloride Attracts moisture


*Potassium acetate CH3COOK -9掳C (15掳F) Biodegradable Corrosive


*Potassium chloride KCl -7掳C (20掳F) Fertilizer Damages concrete


*Sodium chloride (rock salt, halite) NaCl -9掳C


(15掳F) Keeps sidewalks dry Corrosive, damages concrete %26amp; vegetation


*Urea NH2CONH2 -7掳C (20掳F) Fertilizer Agricultural grade is corrosiveIf we use salt to melt ice outside, why do we use salt to freeze ice cream when we make it?
The salt used to melt ice is not the same at all. It is made with chemicals to produce the ';melt';.
Same reason. The ice melts, giving a colder temperature.
Different salt - do NOT use rock salt to make ice cream.
That's poison we'd all die.