Hazardous Black Ice – One Source You May Not Anticipate

Meteorology, Transportation
[caption id="attachment_26551" align="alignright" width="480"] It's night. It's foggy. Is it freezing fog?[/caption]Life is good. Nevertheless, dangers affect everyone - seasonal dangers. In Summer, we may face bees, snakes, rabid animals, poison ivy, deer on the road, chain saw incidents. To name a few. In Winter In winter, the elements become especially problematic. Something as beautiful as snow can sometimes kill. Blinding blizzards, excessive drifts, snow-blinded drivers, even avalanches. One particular danger is not so dramatic. In fact, it is downright sneaky. Black ice. Black Ice Black ice is not actually black, of course, but the word black suggests darkness. Darkness so deep a person with the best of vision can see nothing. One may go outside and fall or drive and have an accident, simply because he does not take…
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What Makes Ice Slippery Compared to Other Solids? A Combination of Factors?

Chemistry, Physics
[caption id="attachment_17673" align="alignleft" width="380"] Image: Tvb hof - Own work, CC BY-SA 3.0[/caption] “Be careful if you will be driving this evening,” the weather forecaster declares. “The road will be a sheet of ice.” Whether tar and gravel, asphalt, or concrete, roads most of the year are not slippery. Yet come winter, those roads can be dangerously slippery. What makes ice and icy roads so slippery? What Makes Ice Slippery One line of thinking is that ice is slippery because water (H₂O) expands as it freezes. When a heavy object rests upon a sheet of ice, the pressure imparts energy to the molecules immediately beneath the weight, pressing them down, melting it. The water acts much like a lubricant, making the ice slippery. In truth, if the ice is reasonably…
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Magnesium Chloride Anti-Icing Spray

Bible, Chemistry
How does your department of transportation deal with winter? Do they use a magnesium chloride anti-icing road treatment ahead of a snow storm? I am a chemist. I live where it snows a number of times each year. Road safety requires local transportation departments to plow during storms. Their efforts are enhanced if preparation is made beforehand. One way to accomplish this is by spraying roads ahead of time with anti-icing spray. Sand Spreading sand does help traction, but it doesn’t prevent or eliminate ice. There is another reason to use something besides sand. Has the reader heard of sandblasting? Particles of sand are blown against a surface to clean it. In fact, it is used to blast away paint from a painted surface. Is that what you want for…
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Transition from Ice to Water to Vapor

[caption id="attachment_5490" align="alignright" width="440"] Hydrogen Bonding - CCA SA 3.0 Unported by Magasjukur2[/caption] The transition from ice to water to steam. What happens? A block of ice has a temperature well below freezing and is warmed gradually. It reaches above the boiling point. What transitions occur along the way? What are the processes? Transition: Solid to Liquid At first, the heat supplied simply increases the temperature of the ice. The temperature of the surface is somewhat warmer than the ice inside. It takes time for heat to penetrate. Eventually, the outer layer of the ice reaches the melting point. The outside ice melts first—then the inner ice. [caption id="attachment_5491" align="alignleft" width="220"] Melting Ice[/caption] During melting, the heat energy is spent breaking the stiff hydrogen bonds. None of it is spent…
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