What Are Supersaturated Solutions?
Answer – A supersaturated solution is a solution that contains more solute than the maximum amount that can be dissolved at a given temperature.
Explanation:
Supersaturation is often achieved by dissolving a solute in a solvent at an elevated temperature and then cooling the solution, preventing the excess solute from precipitating out (recrystallization). If the excess solute comes out of the solution, it forms crystals (crystallization). Here are some examples of supersaturated solutions:
- Saltwater: A supersaturated solution of salt water is made by dissolving an excess amount of salt in hot water and stirring it until fully dissolved. After the solution is cooled, one can continue adding salt, thus making the solution supersaturated. Now, the solution holds more salt than would normally be possible at that temperature.
- Honey: Honey is a naturally occurring supersaturated solution because it contains more sugar than is typical for its water content. The high viscosity (resistance of a fluid) of honey prevents the excess sugar from crystallizing, thus maintaining a supersaturated state.
- Carbonated drinks: Carbonated drinks, such as sodas, are supersaturated with carbon dioxide (CO2) gas. The pressure applied during bottling allows the beverage to hold more dissolved CO2 than it normally would at atmospheric pressure. When the bottle is opened, the excess gas is released as fizz.
