what is an everyday application of boiling-point elevation and freezing-point depression?

Answer 1

freezing-point depression: Ice Cream

boiling-point elevation: Antifreeze in a car's radiator, which provides Boilover protection

Just so you know:
A common mis-attribution of the use of boiling-point elevation is adding salt when cooking foods to elevate the temperature of the water before it boils. However, the temperature increase caused by the amounts of salt added when cooking is generally not enough to raise the temperature by a single degree. The salt is added simply to season the food and prevent pasta from sticking.

http://en.wikipedia.org/wiki/Boiling-point_elevation

Answer 2

To cook Pasta. WHen you boil water to cook pasta , many people usually add salt to the water before it boils. Consequently the water will experience a boiling point elevation and this will allow the water to retain more heat. In order words the water will have to reach a higher temp (and thus retain more heat) inorder boil. This will allow you pasta to be cooked faster.

Obviously by adding a little bit of salt its molality is low and therefore the boiling point elevation will not be signficant. However, the pasta will cook faster. Think about this way

change in heat = mass* C(specific heat of heat of water)(Change in Temp)
Therefore, a pot of water which conatains a couple of kilograms will have overall increase in the heat content even though the change in temp is relatively small. In other words the water will be able to hold a signficant amount of more heat even though the change in temp is small

Answer 3

a boling point elevation is a higher boiling point than a pure solvent.

freezing depression is the point of a solution that is lower than the freezing point of the pure solvent.

Answer 4

An example of feezing point depression is salting roads to melt ice in winter.