If I have a simple syrup made of sugar water, the sugar is dissolved in the water - it is mixed at a molecular level in the water
If I pour the simple syrup through a very fine filter, i will be able to get the sugar out of the water
If i boil the water away, the sugar will be left behind
Boiling water is a chemical change - it changes the molecular structure of the water
dissolving sugar is a chemical change - it changes the molecular structure of the sugar