2006-09-26 21:39:48 · 6 answers · asked by kristine lovele n 1 in Science & Mathematics ➔ Chemistry
colligativve property again.... freezing point depression. if you have any thing dissolve in a solvent the freezing point of the solvent will decrease, i.e. it will freeze at temperature lower than its original freezing point....why salt in ice? once the ice melted it will dissolve the salt near it thn we have a salt soln. this salt soln will then freeze rapidly since its freezing point is lower than those of the pure water. as such the ice will not easily melt. that is the main purpose of putting salt in ice. to prolong the life of the ice so as the ice cream...
best answer?
2006-09-26 21:48:35 · answer #1 · answered by teroy 4 · 0⤊ 0⤋
If you mean the adding of usually rock salt to the water in an ice cream churn, then it has to do with freezing temperature of the water. Salt water will not freeze. But, it will get to below the freezing temperature of fresh water. This means it can also get to below the temperature needed to "ice" the "cream". So, when churcning an ice cream churn to help cause the cream to solidify, it needs to be in a very cold environment. Also, one needs to understand what "heat/hot" and "cold" really are. Cold is technically the absence of heat. Heat energy will go towards where there is less heat energy. In the case of the churn, it will be drawn out from the cream into the water allowing the cream to [have an absence of heat energy or] cool and freeze. With all that heat going into the water from the cream, you don't want the ice to melt since then it wouldn't keep drawing out heat from the cream. The two parts of salty water work hand in hand to keep the temperature down. The salt keeps the water from freezing solid, but the ice in the water helps keep the water cold. Then the cold water helps keeps the ice cubes in cube or ice form which helps keeps the water cold enough to freeze which is prevented from happening by the salt. But, as long asthe watre temp is low enough to freeze, it WILL cause the cream inside the churn to freeze forming ice cream. Did that cycle make sense?
2006-09-27 04:51:08 · answer #2 · answered by quntmphys238 6 · 0⤊ 0⤋
Salt water has a lower freezing point than fresh water and it helps chill the ice cream more quickly. It also drops the temperature well below normal freezing.
2006-09-27 04:49:00 · answer #3 · answered by Warren D 7 · 0⤊ 0⤋
The salt makes the ice melt quicker, so it gets colder. Ice cream needs to be below 32f or 0c, (the normal temperature of ice).
2006-09-27 05:05:43 · answer #4 · answered by Daniel B 2 · 0⤊ 0⤋
Chemical reaction at the molecular level. For instance, put salt in ice water in your picnic cooler and room temp. beer or soda will be ice cold in about 5 to 7 minutes.
2006-09-27 04:44:28 · answer #5 · answered by Rock Ogre 2 · 0⤊ 0⤋
the chem reaction stabilises water at a certain degree, both @ freezing point & @ boiling point.
2006-09-27 04:49:47 · answer #6 · answered by thrag 4 · 0⤊ 0⤋