which of the following is the best reason salt is sometimes spread on icy highways?
1) when a car drives on the ice, the firstion created between the salt and the ice produces heat that melts the ice.
2)when salt chemically reacts with the water, the heat produced melts the ice.
3)the salt obsorbs more sunlight than ice, warming the ice and causing it to melt.
4)the mixture of ice and salt has a lower freezing tempature than water, so the ice melts.
5)the salt contains heat that melts the ice
i picked 2 but not sure!
2 answers
saple solid or liquid
the correct answer is 4.the freezing point of ice decreases when a salt is spread on it. freezing point is temperature at which the vapour pressure is equal to its corresponding solid. when we add salt to it its vapour pressure decreases. are you aware of colligative properties? it is that property of the solution which changes when we add any salt. one of the colligative property is the depression in the freezing point. so this is the reason why we add salt to an ice highway . actually, salt lowers its freezing point and ice melts under same environmental conditions.