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Q:
i would like to know if you guys/girls know anything about what poretrzal salt,table salt, and rock salt are made up of and how fast do they melt ice cubes
- donnie (age 14)
beaver,pa,usa
A:
Hi Donnie,
The salt used on pretzels is the same kind of salt in the salt
shaker on the table, is the same kind of salt found in bags of rock
salt. It's all sodium chloride, NaCl.
Actually, some people are concerned about their sodium intake and
substitute potassium chloride for sodium choride some of the time, but
this is uncommon. I don't like potassium chloride on my food. Some
fancy table salt is "sea salt", which also contains mixtures of calcium
chloride and other minerals found in the sea. Table salt (and pretzel
salt) also usually contain a small amount of added iodide, a vital
nutrient. None of these differences should have any effect on how well
it melts water.
What may have an effect is how finely ground up the salt is. Rock
salt comes in big chunks and only will help melt the ice it comes in
contact with or ice that gets water on it containing salt dissolved
from the big crystals. Finely ground-up salt presents more surface area
and more rapid updake of the salt by the melting water. If the salt is
first dissolved in water, it won't make any difference which one is
used.
Tom
(published on 10/22/2007)
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