Do you know that salt is used widely in cold countries to melt the ice or snow on the roadways faster during winters? It is believed (actually proven that) that salt lowers the freezing or melting point of water. Do you know that water freezes at 0 oC or 32 oF? This means at 0 oC or 32 oF water will turn to ice. A 10% salt solution drops that freezing point to -6 oC or 20 oC. More the percentage of salt more the decline of water’s melting point. Let’s see whether it is true or not. Let’s see the relationship between salt and melting point (or freezing point).
Does salt stimulate the melting of Ice?
Things that you need:
- Three equal cubes of ice (You can use three perfectly similar molds to make ice in them with equal amount of water)
- Three cups of equal size with exactly equal amount of water
- Project data card
Step 1: Label the first cup as ‘control’, the second cup as ‘low salt’, and the third cup as ‘high salt’
Step 2: In the cup labeled ‘low salt’ mix 1 tea spoon of salt and blend well to dissolve all the salt dusts.
Step 3: In the cup labeled ‘low salt’ mix 2 tea spoons of salt and blend well to dissolve all the salt dusts.
Step 4: Now take the help of a person to start the stop watch as you drop the ice cubes into the cups (drop an ice cube in each cup).
Step 5: Record the time taken for each cup to dissolve the ice completely.
Step 6: Repeat the procedures in a different order. This time insert the ice cubes before adding salt and do not mix the salt or try to dissolve the salt. Record the times once again. Compare everything and write your report.
Project data chart: