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A colligative property is a quality of a substance determined by the number of particles (molecules or atoms) present but not by the nature of the particles. Two examples of colligative properties are the pressure of an ideal gas and the lowering of a solvent’s freezing point due to dissolved particles. The word “colligative” is derived from the Latin word “colligatus,” which means “to be tied together or bound together.” The examples of colligative properties are useful when defining a solution. They show how the properties of the solution are related to the concentration of solute in the solution.
Continue reading to understand the importance of colligative properties and their examples.
Why Are Colligative Properties Important?
Vapour pressure lowering, boiling point elevation, freezing point depression, and osmotic pressure are all examples of colligative properties. This little cluster of dwellings has significant implications for a variety of herbal phenomena and technology applications, as explained in this module.
Colligative Properties Examples
We may take a look at the colligative properties of solutions by looking at the following instances.
- When we add a pinch of salt to a tumbler full of water, the freezing point drops significantly below the normal value. Alternatively, its boiling temperature rises, and the solution may have a lower vapour pressure. There are also changes in its osmotic stress.
- Similarly, when we add alcohol to water, the solution’s freezing point drops below the normal temperature. This is true for both natural water and alcohol.
Different Types of Solution Colligative Properties
There are several different types of colligative properties for a solution:
Freezing point depression:
Solution freezing points are lower than the freezing points of pure solvents. The lowering of the freezing point is related to the molality of the solute. The freezing point of water is lowered when sugar, salt, alcohol, or any other substance is dissolved in it.
Other than water, the effect operates, although the amount of temperature change varies depending on the solvent.
Boiling point elevation:
The boiling factor of a liquid is the temperature at which the vapour strain equals the ambient strain. We know that adding a non-unstable liquid to a natural solvent reduces the solution’s vapour strain. We need to raise the temperature of the solution to make the vapour strain equal to the ambient strain.
The difference between the boiling factor of the solution and the boiling factor of the natural solvent is referred to as an elevation in the boiling factor.
Vapour pressure lowering:
In a natural solvent, the molecules of the solvent take up the entire floor. When a non-stable solute is added to a solvent, the floor now contains both the solute and the solvent molecules, reducing the number of solvent molecules blanketing the floor.
The vapour strain of the solution is smaller than that of the natural solvent at the same temperature since the response’s vapour strain is purely due to the solvent.
Osmotic pressure:
When a semipermeable membrane is placed between a solution and a solvent, solvent molecules pass through the membrane and enter the solution, increasing its volume. The most effective solvent molecules can pass across this semipermeable barrier, while larger molecules like solute cannot.
A solution’s osmotic pressure is proportional to the solute’s molar concentration. As a result, the higher the osmotic pressure of the solution, the more solute dissolved in the solvent.
The relationship between osmotic pressure and solute concentration is described by the Van’t Hoff equation.
Working of Colligative Properties
The dissolved particles displace some of the solvent in the liquid phase when a solute is introduced. This lowers the solvent concentration per unit of volume. The kind of particles are not important; what matters is how many of them there are.
For example, completely dissolving CaCl2 gives calcium and chloride particles. However, dissolving NaCl yields just two particles (a sodium ion and a chloride ion). Table salt would have a stronger effect on colligative characteristics than calcium chloride. Therefore, calcium chloride is a more efficient de-icing agent than common salt at lower temperatures.
Conclusion
Friedrich Wilhelm Ostwald, a chemist and philosopher, coined the term “colligative properties” in 1891. Colligative properties help us understand how the properties of the solution are connected to the attention of a solute within the solution while we’re describing it.
The four often researched colligative properties are the freezing factor, boiling factor elevation, vapour stress-reducing, and osmotic stress. Because such residences provide data in the range of solute debris in solution, they can determine the solute’s molecular weight. Brushing up on some questions on the examples of colligative properties can help one understand the concept better.
