The situation described, where the last spoonful of sugar won't dissolve in your coffee regardless of how much you stir, indicates that you have created a saturated solution. In a saturated solution, the solvent (in this case, coffee) has dissolved the maximum amount of solute (sugar) possible at that temperature and pressure. Any additional solute added will not dissolve.
When you are dissolving sugar in your coffee, the last spoonful of sugar won't dissolve no matter how much you stir. What type of solution have you made?
A colloid solution
An emulsion solution
A saturated solution
A supersaturated solution
1 answer