What Is a True Solution Definition Characteristics Particle Size and Examples
A clear, homogeneous mixture of a solute and a solvent having a particle size of <1nm is called a true solution. Solute and solvent in a true solution are completely dissolved. They cannot be passed through filter paper and even cannot be seen through a microscope. Solute and solvent are the components of a true solution and a uniform mixture.
Both the Tyndall effect and the Brownian movement can not be observed in a true solution. The solution is transparent and solute particles do not settle down because of their very small size. The particles of solute in the true solution do not settle down. This makes it different from the colloidal solution. Example- solution of sugar and salt in water.
What is a True Solution?
When a solute and solvent are mixed together homogeneously, this type of mixture is known as a true solution. It has a particle size of <1nm. It is a homogenous mixture of solute and solvent. In a true solution, both solute and solvent pass through the filter paper. A true solution does not scatter light, that is, it does not show the Tyndall effect. Filtration cannot separate the particles. Hence, it is a uniform solution throughout. Due to homogeneity, the particles of solute do not settle down. It is a clear and transparent solution.
Components of True Solution
There are two main components of the solution. These are as follows:
Solute - It is that part of a solution that is dissolved in the solvent.
Solvent - It is that part of the solution in which solute dissolves. It defines the phase of solution and it is in larger quantities than solute.
Difference between True Solutions and Colloidal Solutions
A true solution is a homogenous mixture of solute and solvent, whereas a colloidal solution is a heterogeneous mixture in which solute remains suspended in a solvent.
The size of particles in a true solution is <1 nm, whereas in a colloidal solution, the size ranges from 1 nm to 100 nm.
In a true solution, the Brownian effect cannot be observed, whereas it can be observed in a colloidal solution.
Particles cannot be seen even with a microscope in true solution, whereas particles in colloidal solution can be observed with a microscope.
True solutions do not show the Tyndall effect whereas colloidal solutions show.
Properties and Characteristics of True Solution
Are you aware which properties are characteristic of true solutions? The following points discuss the properties and characteristics of true solutions.
The true solution is a homogeneous mixture.
The particles cannot be seen through the naked eye or a microscope.
The particles of the solution easily pass through the filter paper, and hence it is impossible to separate them.
It has only one phase.
The physical and chemical properties such as melting and boiling point of a true solution change when other substances are added to it.
What is the Real Solution?
The real solution definition states that it is a homogeneous mixture of at least two chemical substances. The real solution is clear and particles are evenly distributed in the solvent.
Conclusion
In conclusion, we have learnt that a true solution is a homogeneous mixture of two or more substances. The solute completely dissolves in solvent and forms a colourless, transparent solution. The particle size of a true solution is 1nm. An example of a true solution can be salt or sugar solution in water. The types of true solutions are based on various factors.
The properties of the true solution make it different from suspension and colloidal solutions. The solute and solvent of the true solution do not settle down at the bottom. Therefore, the light completely passes through it. That is, it does not show Tyndall or Rayleigh’s effect. Brownian motion is also not observed in true solution. The particles are so small that they cannot be observed by the naked eye.
FAQs on True Solution in Chemistry with Definition and Key Properties
1. What is a true solution in chemistry?
A true solution is a homogeneous mixture in which a solute is completely dissolved in a solvent at the molecular or ionic level. In a true solution, the particle size of the solute is less than 1 nm, so the particles are not visible and do not settle on standing.
- It has uniform composition throughout.
- The solute particles cannot be seen even under a microscope.
- Example: NaCl(aq) formed when sodium chloride dissolves in water.
2. What are the main characteristics of a true solution?
The main characteristics of a true solution are homogeneity, very small particle size, and stability without settling. Key properties include:
- Particle size less than 1 nm.
- Uniform composition throughout the solution.
- No Tyndall effect (does not scatter light).
- Particles do not settle on standing.
- Cannot be separated by ordinary filtration.
3. What is the difference between a true solution, colloid, and suspension?
A true solution has molecular-sized particles (<1 nm), a colloid has intermediate particles (1–1000 nm), and a suspension has large particles (>1000 nm). The key differences are:
- True solution: Homogeneous, no Tyndall effect, no settling (e.g., sugar in water).
- Colloid: Appears homogeneous but shows Tyndall effect (e.g., milk).
- Suspension: Heterogeneous, particles settle on standing (e.g., sand in water).
4. Why does a true solution not show the Tyndall effect?
A true solution does not show the Tyndall effect because its solute particles are too small to scatter light. Since particle size is less than 1 nm:
- Light passes through without scattering.
- The path of the light beam is not visible.
- The solution appears completely transparent.
5. Can you give examples of true solutions?
Common examples of true solutions include salt in water, sugar in water, and air. Examples in chemistry are:
- NaCl(aq) – sodium chloride dissolved in water.
- C12H22O11(aq) – sugar dissolved in water.
- Air – a gaseous true solution mainly of N2 and O2.
6. How is a true solution formed?
A true solution is formed when solute particles dissolve completely in a solvent due to intermolecular interactions. The process involves:
- Breaking solute–solute interactions.
- Breaking solvent–solvent interactions.
- Forming solute–solvent interactions.
7. What is the particle size in a true solution?
The particle size in a true solution is less than 1 nanometer (1 nm). Because of this extremely small size:
- Particles are invisible to the naked eye and under a microscope.
- They pass through filter paper.
- The solution remains stable without sedimentation.
8. Can a true solution be separated by filtration?
A true solution cannot be separated by ordinary filtration because the solute particles are too small to be trapped by filter paper. However, separation is possible by:
- Evaporation (removing solvent).
- Distillation (based on boiling point differences).
- Crystallization (recovering solid solute).
9. Is air a true solution?
Yes, air is a true solution because it is a homogeneous mixture of gases uniformly distributed at the molecular level. Air mainly contains:
- N2 (~78%)
- O2 (~21%)
- Small amounts of CO2 and noble gases
10. What are the types of true solutions based on physical state?
True solutions are classified into solid, liquid, and gaseous solutions based on the physical states of solute and solvent. The main types include:
- Solid in liquid: NaCl in water.
- Liquid in liquid: Ethanol in water.
- Gas in liquid: CO2 in water (carbonated drinks).
- Gas in gas: Air.
- Solid in solid: Alloys like brass (Cu–Zn).
