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Showing posts from October, 2018

Salt and ice effect

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In our part of the world, temperatures are low enough in winter for snow and ice to form. This can make driving and walking dangerous as roads and sidewalks become slippery. In western New York, rock salt is often used to melt icy roads. The interaction of salt and ice is an interesting thing to explore. Put two ice cubes in two glasses. Put a teaspoon of table salt on one ice cube. Which ice cube melts faster, the one with the salt or the one without the salt? Why does this happen? The ice cube without salt melts because the air around it is warmer than 32 degrees F. The salted cube melts faster. When you add salt it dissolves into the water of the ice cube. Saltwater freezes at a lower temperature than the 32 degrees F at which freshwater freezes. The difference between the air temperature and the freezing point of salt water is bigger than the difference between the air temperature and the freezing point of freshwater. This makes the ice with salt on it melt fa