Salt is put down on sidewalks and roads to melt ice, but adding salt to ice water is the fastest way to chill a bottle of wine (which seems to imply the the salt makes the ice colder). Are these different types of salt? Or are they phenomenon that are distinct and perceived differently (i.e. the salt doesn't actually make the water colder, that's just the way we perceive it)?
2007-02-15 00:07:51 · 6 answers · asked by AB 2 in Environment
Salt dissolved in water changes the freezing temperature of the water... i.e salt does make the water colder !
So water without salt (fresh water) will freeze at a higher temperature than water with salt.. the actual temperature depends on the type and quantity of salt..
Now water ice is 0°Celsius... and no matter how cold the air gets the ice will NOT get any colder.. ice formed by freezing seawater or brine is 100% pure water ... also with a melting point of 0°C.
Eskimos use snow ice to make shelters to stay warm ... if you can call that warm...
The addition of salt changes the equilibrium of the water/ice mixture allowing water to actually get colder than its normal freezing point.
The wine bottle gets colder because the ice melts and the resulting water comes into more uniform contact with the bottle transferring energy more effectively than ice which isn't melting.
Salt is put on roads to prevent the ice from forming and to melt the ice, but this action is not unique. Sugar, alcohol, or other salts will also lower the freezing point and melt the ice. Salt is used on roads and walkways because it is inexpensive and readily available.
When salt enters solution with water the point at which water can stay frozen rises, resulting in the ice melting.
Check out the supplied link.
2007-02-15 00:38:33 · answer #1 · answered by AnselRoe 2 · 0⤊ 0⤋
Adding salt to water lowers its freezing point to something less than 32F or 0C.
Ice absorbs heat from its surroundings as it melts (Heat of fusion). Adding salt to the ice causes the ice to melt faster. The rate of heat flow from one object to another (hotter source to colder sink) is based upon the delta Temp between the source and sink. So if you can increase the rate of heat flow it would mean that you would have to lower the temperature that the heat is flowing to in order to accommodate the higher heat flow.... SO by melting the ICE faster you are absorbing surrounding heat faster (increased heat flow) using up the heat of fusion stored in the ice at a faster rate. This has the effect of lowering the temperature to a point which would be a lower temperature (giving a larger delta T) which supports the increase heat flow
i.e. Melt the ICE faster it gets colder as long as ther is melting ICE
2007-02-15 00:50:33 · answer #2 · answered by MarkG 7 · 0⤊ 0⤋
Salt on the roads dissolves and lowers the freezing point of the water on the road. The salt used in an ice cream maker is used on the ice on the outside, not in the ice cream mixture. It lowers the freezing point of the ice and that lowers the temp of the ice cream, freezing it. When ice melts it takes energy. This energy is withdrawn from the ice cream mix
2016-05-24 02:58:12 · answer #3 · answered by ? 4 · 0⤊ 0⤋
Salt decreases the freezing point of water that is all I know .
2007-02-15 00:18:18 · answer #4 · answered by xeibeg 5 · 0⤊ 0⤋
salt acts as a freezing mixture
2007-02-15 00:17:13 · answer #5 · answered by mishty 1 · 0⤊ 1⤋
if you subsitute the multiplication table this will be for homework.......
2007-02-15 00:12:08 · answer #6 · answered by Anonymous · 0⤊ 1⤋