06 March 2009

The mystery of the reappearing salt

Do you remember our investigation into dissolving?  How we stirred the same amount of some different materials into the same amount of water using the same number of stirs?

And do you remember how the salt disappeared or dissolved in the water?

Well, we kept the beaker with the clear salt solution, and by the next week, the level of salt-water had gone down.  Some of the water had evaporated.

Another week passed, and the water-level had gone down even further.

By the end of the week, there was barely any water left at all.  But there was some white stuff on the sides of the beaker…..


as well as some tiny cubes of something at the bottom.


A brave tester confirmed that the white stuff tasted salty.  Could it be that we had managed to get the salt back out of the water it had been dissolved in?

Do you think we could do the same with dissolved sugar?

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