Solubility
The amount of a solute that can be dissolved in a solvent.
Solubility is the ability of a solute to dissolve in a solvent. The solubility of a substance in another is not unlimited, and how much solute you can solve in a solvent varies a lot. Tabulated values of solubility refer to max grams of solute in a given amount of the solvent.
- solubility is dependent on temperature. In general, but not without expectations, solubility increases with temperature
- smaller particles dissolves faster than larger particles
- a solid dissolves faster if the mixture is stirred or shaken
A saturated solution contains the maximum amount of solute in the solvent, given by the solubility.
Examples of common solutions:
- tea with sugar - a solution of sugar in hot water (tea)
- seawater - a solution of salt in water
See more at Solutions, molarity and dilution
See also solubility product constants and solubility guidelines for ionic compounds in water
Example 1
Sodium chloride, NaCl, is the salt used for cooking. This salt has a solubility of 36 g in 100 g of water at 25°C.
What is the concentration (in wt%) of a saturated NaCl water solution at 25°C?
A saturated solution contains the maximum amount of solute in the solvent, which for NaCl is 36 grams in water at 25°C. Then, the concentration of the saturated solution is: g NaCl /g NaCl solution *100%
NaCl concentration = 36 [g]/(100 + 36)[g] * 100% = 26.5 wt%
Example 2
What will be the concentration (in wt%) if you add 34 g NaCl to 100 g of water?
34 g NaCl is less than the solubility, which means that all the salt will be solved in water at 25°C.
NaCl concentration = 34 [g]/(100+34) [g] * 100% = 25.4 wt%
Example 3
What will be the concentration (in wt%) of the salt solution if you add 38 g NaCl to 100 g of water?
38 g NaCl is more than the solubility of NaCl in water. This means that the solution will be saturated and some of the salt will remain undissolved at 25°C. The concentration of the saturated solution is the same as in Example 1:
NaCl concentration = 36 [g]/(100 + 36)[g] * 100% = 26.5 wt%