Why does adding salt to ice in an ice cream maker, make the temp. colder?

Question

the creams does not start to freeze until you add salt. on myth busters the temp of ice went blow freezing when salt was added as compared to when salt was not added to ice

Answer 1

Salt added to ice causes an immediate PHASE CHANGE from pure water to salt+water which has a much lower freezing point. That phase change results in a huge amount of Cooling calories being released into the surrounding salt +water, that release in calories ( negitive calories) is what drops the temperature of the ice+water.

The phase change here is of course NOT to pure water, it is a phase change to water+salt which has a much lower freezing point.

Answer 2

INGREDIENTS CRUST 225 g Cadbury Dairy Milk Wafer biscuits, crushed 110 g butter, melted FILLING 2 litres vanilla ice cream ½ cup cream 2 tablespoons Crème de Caçao 2 Cadbury Flake Bars, crushed TOPPING ½ cup caster sugar 1½ cups cream 30 g butter 100 g (4 rows) Cadbury Dark Cooking Chocolate, chopped 1 teaspoon vanilla essence SAUCE 1/3 cup reduced cream 50 g (2 rows) Cadbury Dark Cooking Chocolate, chopped 1 teaspoon Crème de Menthe Make the crust first. Combine the biscuit crumbs with the butter. Press the mixture into the base of a 23 cm springform pan. Make the filling next. Beat together the ice cream, cream and Crème de Caçao. Fold the crushed Flake Bars through the mixture. Spread the ice cream mixture over the crust and freeze for about 2 hours until firm. Make the topping. In a saucepan heat the caster sugar, cream and butter until melted. Remove from the heat and stir in the dark chocolate until melted. Add the vanilla essence. Pour over the frozen ice cream and freeze for a further 1-2 hours. Make the sauce. Bring the cream to the boil in a saucepan. Whisk in the chocolate until melted. Cool. Stir in the liqueur. Dust the torte with sifted icing sugar if desired, and serve with the sauce spooned over. Enjoy

Answer 3

Just because water freezes at 32 degrees, doesn't mean that ice is 32 degrees. When you take the ice out of the freezer, it is much colder than that. There overall tempurature does not decrease, it's just that salty water freezes at a temp. lower than that of pure water.

Answer 4

It makes the ice melt which makes the temperature drop below freezing. Great for getting pop and beer cold fast also! Place your cans or bottles of pop or beer in ice and then sprinkle salt over the ice and boy does it ever get cold!!