Key Words Description Students are given weighed samples of a soluble salt such as potassium nitrate. The sample is added to 20 mL of water and heated until all of the salt dissolves. The solution is cooled, and the temperature at which solid appears is noted. A solubility curve is prepared by pooling the data from all of the students. For all solids there is a limiting amount that will dissolve in a given amount of solvent.
Some solids are very soluble in water, while others are nearly completely insoluble.
The solubility of a solid in a given solvent depends on the temperature of the solution. Usually the solubility of a solid increases with increasing temperature, sometimes very markedly. A graph which plots the solubility as a function of temperature is called the solubility curve of the substance. Given such a graph, the solubility of the solid at any temperature may be determined. Go to Top Hazards Burns when handling hot objects are possible.