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!
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.
To determine the correct answer to the question, let's go through each option and explain how to arrive at the answer:
1) When a car drives on the ice, the friction created between the salt and the ice produces heat that melts the ice.
This option is incorrect. While it is true that friction can generate heat, the heat produced by the friction between salt and ice is not sufficient to significantly melt the ice on highways.
2) When salt chemically reacts with the water, the heat produced melts the ice.
This option is correct. Salt, such as sodium chloride, when applied to icy surfaces, dissolves in the thin layer of water created by the ice. This dissolution process is an exothermic reaction, meaning it releases heat. The heat generated from this reaction helps to melt the ice.
3) The salt absorbs more sunlight than ice, warming the ice and causing it to melt.
This option is incorrect. While it is true that some substances may absorb more sunlight and become warmer, the reason salt is spread on icy highways does not rely on the absorption of sunlight.
4) The mixture of ice and salt has a lower freezing temperature than water, so the ice melts.
This option is incorrect. While it is true that mixing ice with salt creates a lower freezing point for the resulting solution, this is not the primary reason for spreading salt on icy highways.
5) The salt contains heat that melts the ice.
This option is incorrect. Salt itself does not contain heat. However, as explained in option 2, when salt reacts with the thin layer of water created by the ice, it releases heat, which contributes to the melting process.
Based on the explanations, option 2 is the best reason for why salt is sometimes spread on icy highways.