Ask A Scientist Chemistry Archive

name         Bob P.
status       other
age          30s

Question -   Why is ice made from demineralized water(0 ppm tds)much
harder than ice made from mineralized water?
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I do not know much about chemistry, but I suspect that the hydrogen and
oxygen elements are held closer together because of the absence of
minerals? (would that be a good guess?)
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There probably is no single answer, but several contributing factors. The
minerals in water cause stresses and various imperfections in the crystal
structure. These will produce dislocations that are weak compared to the
structure of pure ice. The presence of dissolved air has a similar effect.
Your guess is pretty good.

Vince Calder
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