Why does a sugar substitute that dissolves when a drink is hot stay at the bottom of the cup when it cools down?

Answer 1

The higher the temperature of a liquid, the more of a substance it can dissolve. So when a liquid cools back down, often some of the dissolved particles re-form into solid and precipitate out of the solution. This applies to sugar substitute as it does to any other substance. Just like regular sugar dissolves in your coffee better when your coffee is hot.

Answer 2

Sugar crystals are more dense than water, and that's why they fall to the bottom of a glass of iced tea. It's like adding a teaspoon of sand to the tea. Certainly the sugar isn't as dense as the sand, but the effect is the same, and the sand was used simply as an example.

Answer 3

Warm liquids more readily dissolve solutes in a solution. The hotter the liquid, the more energy the solution has to counteract the addition of a new substance. It is energetically unfavorable for a solute such as sugar to remain dissolved in a solution (like is attracted to like). Moreover, the freezing point of table sugar is much higher than that of water. Thus, for all these reasons sugar deposits itself out of the solution when the temperature is lowered. The hot tea, because of it's temperature, can absorb more sugar than cold tea. When the temperature is lowered, less can be dissolved in solution and this, along with the driving force to separate like with like, causes the deposits of solid sugar on the bottom of the glass.

Answer 4

Solubility is affected by temperature. Generally, the warmer a solvent, the more solute it can dissolve. If the solution cools, the solvent may not be able to dissolve as much solvent, and the solute comes out of solution.

Answer 5

I believe that's called supersaturation. (Not 100% sure)