Viewing a single comment thread. View all comments

BurnOutBrighter6 t1_iy22sfq wrote

When water freezes, all the individual water molecules (which are roughly "V" shaped) click together into a highly structured repeating 3D crystal pattern that looks like this. Note all the waters form hexagons, kind of like a honeycomb - that's why snowflakes are hexagonal and have 6-sided symmetry.

So yes the water does "purify" itself as it crystallizes into solid ice. Basically, the salt molecules don't really fit or snap into this hexagonal pattern very well, so they mostly get left behind as all the waters start clicking together into their big solid scaffold.

12

ScienceIsSexy420 t1_iy2a8vp wrote

This is why salt, and other dissolved compounds, will reduce the freezing temperature of water: the interfere with the formation of the crystal lattice structure required for the phase transition

5