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The good news is you don't need a pool of water to achieve the effect. Ice typically is coated with a thin film of liquid water, which is all it takes. Water with salt or any other substance in it will freeze at some lower temperature. Just how low this temperature will be depends on the de-icing agent. If you put salt on ice in a situation where the temperature will never get up to the new freezing point of the salt-water solution, you won't see any benefit.
If the temperature gets down to where the salt water can freeze, energy will be released when bonds form as the liquid becomes a solid. This energy may be enough to melt a small amount of the pure ice, keeping the process going. You can demonstrate the effect of freezing point depression yourself, even if you don't have an icy sidewalk handy.
One way is to make your own ice cream in a baggie , where adding salt to water produces a mixture so cold it can freeze your treat. If you just want to see an example of how cold ice plus salt can get, mix 33 ounces of ordinary table salt with ounces of crushed ice or snow. Be careful! Table salt dissolves into sodium and chloride ions in water. Sugar dissolves in water, but does not dissociate into any ions.
What effect do you think adding sugar to water would have on its freezing point? Can you design an experiment to test your hypothesis? Putting salt on water isn't the only time freezing point depression occurs.
Any time you add particles to a liquid, you lower its freezing point and raise its boiling point. Another good example of freezing point depression is vodka. Vodka contains both ethanol and water. Ordinarily, vodka does not freeze in a home freezer. The alcohol in the water lowers the freezing point of the water. Actively scan device characteristics for identification. This investigation uses salt to supercool an ice and water mixture cooling the drink inside very quickly!
Making frost on a can is easy if you have salt, ice cubes and a tin can. This is our Frosty the Snowman, but you could theme this investigation however you wanted. Try some painting on ice. This is one of my favourite ice activities as ice is a lovely medium to paint over. Make some ice decorations and hang them outside. Investigate how to make the best ice hockey puck.
Try some colour mixing and make slushy drinks with ice. Make some baking soda ice cubes and vinegar and watch them fizz.
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