Get a reasonable amount of cold tap water. Say 450 ml (about 18 oz).
Get 3 containers, each big enough to hold about 150 ml of water in them. One of these (container 3) must be suitable for holding a hot liquid in it.
Container 1:
Add 150 ml cold water.
Stir a single dinner spoon-full (about 7 g) of sugar in. The sugar will all dissolve, creating an unsaturated solution.
Container 2:
Add 150 ml cold water.
Slowly stir single dinner spoon-fulls (about 7 g each) of sugar in. The sugar will keep dissolving, but eventually the water will become saturated -- as full of sugar in solution as it can get. Finally grains of sugar will appear at the bottom of the container. The solution is saturated.
Container 3:
Heat 150ml water to just short of boiling point (eg, in the microwave). Then quickly stir in lots of sugar. The hot water will absorb more sugar than the cold water did, meaning that if you add enough sugar it will be a supersaturated solution .
Eventually Container 3 cools and the sugar starts precipitating out; a supersaturated solution is inherently unstable.
Get 3 containers, each big enough to hold about 150 ml of water in them. One of these (container 3) must be suitable for holding a hot liquid in it.
Container 1:
Add 150 ml cold water.
Stir a single dinner spoon-full (about 7 g) of sugar in. The sugar will all dissolve, creating an unsaturated solution.
Container 2:
Add 150 ml cold water.
Slowly stir single dinner spoon-fulls (about 7 g each) of sugar in. The sugar will keep dissolving, but eventually the water will become saturated -- as full of sugar in solution as it can get. Finally grains of sugar will appear at the bottom of the container. The solution is saturated.
Container 3:
Heat 150ml water to just short of boiling point (eg, in the microwave). Then quickly stir in lots of sugar. The hot water will absorb more sugar than the cold water did, meaning that if you add enough sugar it will be a supersaturated solution .
Eventually Container 3 cools and the sugar starts precipitating out; a supersaturated solution is inherently unstable.
