

An Overview of Experiment For Class 9 Chemistry Solution Colloids Suspension
Introduction
Colloidal solutions are among the important components of a mixture along with the two neighbouring combinations, true solutions, as well as suspension solutions. The differences between the three solutions are mostly due to the size, appearance, and method of particle separation, which vary in all three solutions under various physical and chemical conditions. With distinct chemical reactions, the three solutions behave in different ways. The dissolving characteristics of the three mixtures, which vary depending on the solute and solvents used, are what gives them their distinctive characteristics.
Table of Content
Aim
Preparation of Solution of Sodium Chloride in Water
Preparation of Colloidal solution of Milk in Water
Preparation of Suspension Solution of Chalk Powder in Water
Result
Aim
To distinguish between the pure solution, colloidal and suspension based on:-
Transparency
Scattering
Filtration
Apparatus Required
Sodium chloride, milk, chalk powder, water, test tube, glass rod, test tube holder, funnel, beaker, and filter paper.
Theory
Properties of Solution
It is a uniform mixture. To the naked eye, the particles are invisible. Since particles don't scatter light when it passes through them, the direction of the light cannot be seen. The mixture cannot be separated from solutes, and they do not settle. A stable solution exists. Filtration cannot separate the constituents of a mixture.
Properties of Colloidal Solution
In nature, colloids are comparatively stable. It is a heterogeneous mixture which is not visible to the naked eye. The dispersed phase's particles continue to move continuously and are suspended in the solutions. Ultrafilters are specialized filters needed for the filtration of colloids.
Properties of Suspension
The mixture is heterogeneous. The suspension mixture's particles are visible to the naked eye. The Tyndall effect can be seen in suspension. It indicates that a beam of light travelling through a particle's suspensions will be reflected, illuminating its path. Particles in a suspension settle down if they are not disturbed. It demonstrates that suspension is a volatile substance. The suspension will not exhibit the Tyndall effect in this situation. Filtration can be used to separate suspension particles.
Procedure
Preparation of Solution of Sodium Chloride in Water
In a sterile, dried beaker, add 100 mL of distilled water to it.
Then fill it with dry common or (sodium chloride) salt.
Using a glass rod, stir the mixture. To achieve a true solution, common or (sodium chloride) salt thoroughly dissolves.
Make a note of the observations.
Preparation of Colloidal solution of Milk in Water
In a beaker, add 10 ml of water.
Then add a tiny amount of milk to it. Using a glass rod, properly stir the mixture. Next, while constantly swirling, pour 90 mL of distilled water and add a couple of drops of dilute acid (dil. H2SO4, and HCl).
Make a note of the observations.
Preparation of Suspension Solution of Chalk Powder in Water
In a beaker, take 10 g of chalk powder.
Then add 100 mL of distilled water to a beaker containing chalk powder.
Mix thoroughly, then note the observation seen.
Observations
Result
The results of the chemistry experiment solution colloids suspension verified that
Sodium chloride (NaCl) in water is a true solution.
Milk in water is a colloidal solution.
Chalk powder in water is a suspension solution.
Precautions
Handle chemicals and apparatus with caution.
Every apparatus should be rinsed with distilled water, and dried before starting the experiment.
While heating or boiling, utilize a test tube holder.
Prepare solutions using only distilled water.
Use a glass rod to transfer the mixtures into the funnel during filtration.
Throughout the stability testing, don't tamper with the mixture.
After the completion of the experiment, wash your hands thoroughly.
Lab Manual Questions
1. What type of filter paper is used in labs to filter the colloidal solution?
Ans: Whatman filter paper which is made up of alpha-cellulose is used normally in labs.
2. What types of methods are used to separate the constituents of homogeneous and heterogeneous mixtures?
Ans: Separation methods like filtration, evaporation, simple distillation, etc. can be used to separate constituents of homogeneous mixtures. For heterogeneous mixtures, methods like centrifugation, filtration, etc. can be used to separate the constituents.
3. Why is dilute acid added during the preparation of the colloidal solution?
Ans: During the preparation of colloidal solution is used to raise the ionization of water.
4. Why not concentrated acid be added during the colloidal solution preparation process?
Ans: When using concentrated acids, like HCl, the reaction is extremely violent and the mixture gets hot. This speeds up the process much more, and the liquid within may foam. The process is significantly under control when the acid is diluted.
Viva Questions
1. What is a Suspension Solution?
Ans: A combination of two or more compounds in which the particles do not disperse.
2. Mention two examples of colloidal solution
Ans: Butter, and paint
3. What is meant by sol?
Ans: A sol is indeed a colloid where the liquid serves as the dispersion medium and the solid dispersed phase.
4. What are lyophilic sols?
Ans: A sol wherein dispersed phase and medium possess the strong force of attraction.
5. What are lyophobic sols?
Ans: A sol that cannot be created by simply mixing the dispersed phase in the dispersion medium.
6. Mention examples of lyophilic sols.
Ans: Starch, protein, etc.
7. Mention the examples of lyophobic sols.
Ans: Metal sulphides, and hydroxides.
8. What is the difference between solution and suspension?
Ans:
9. Mention the solvent and solute in the sugar solution.
Ans: Solvent-water, solute-sugar.
10. What are the three types of colloidal solutions other than sol?
Ans: Emulsion, aerosol, and foam.
Practical-Based Questions
1. What happens when egg albumin is added to boiling water?
Soluble
Insoluble
Produces insoluble coagulates
Neither of the three options
Ans: When egg albumin is added to the boiling water, it produces insoluble coagulates.
2. Which one of the following statements is valid?
The particle of egg albumin in water is visible to the naked eye
The particles of egg albumin in water are invisible to the naked eye
The particles of egg albumin in water are also invisible under a microscope
The particles of egg albumin in water are visible to the naked eye and under a microscope.
Ans: The particles of egg albumin in water are invisible to the naked eye.
3. How to prepare a colloidal solution of starch?
Add starch to hot water.
Add starch to cold water.
Add starch to boiling water.
Add starch to normal water
Ans: To prepare a colloidal solution, add starch to hot water.
4. In aerated drinks, what is the solute?
Solid
Liquid
Gas
Gel
Ans: The solute of the aerated drink is gas.
5. Mention the colloidal solution in which both solute and solvent are liquid?
Emulsion
Foams
Aerosols
Gel
Ans: The colloidal solution in which both solute and solvent are liquid is an emulsion.
6. Which of the following solutions does not leave residue during filtration through filter paper?
True solution
Colloidal solution
either of true and colloidal solution
both true and colloidal solution
Ans: Both true and colloidal solution does not leave residue during filtration through filter paper.
7. Which one of the following statements is valid?
A saturated solution does not dissolve at a certain temperature.
The saturated solution dissolves at a certain temperature.
The saturated solution dissolves at varied temperatures.
The saturated solution does not dissolve at varying temperatures.
Ans: Saturated solution does not dissolve at a certain temperature.
8. How does distilled water act in chemical laboratories?
Indicator
Solvent
Universal solvent
None of the three option
Ans: Distilled water acts as a universal solvent in chemical laboratories.
9. Choose the best application of suspension from the following options?
Flour in water-food
Ballpoint pens
Salt in water-salt solution
Lotions
Ans: The application of suspension is flour in water food.
10. Mention the colloid from the following, in which solid is the dispersion medium and gas is the dispersed phase?
Butter
Pumice stone
Milk
Ink
Ans: Pumice stone is the colloid in which solid is a dispersion medium and gas is the dispersed phase.
Conclusion
This chemistry experiment on solution colloids suspension infers that the colloidal solutions, such as milk in water, true solutions, such as sodium chloride in water, and suspensions, such as chalk in water, differ depending on the types of particle size, solutes, and solvents used; the mixture depends on the solubility ratio of the individual particles. Since the solvent and the solute are completely combined, a solution must be completely incompatible. These variations can be seen in these mixtures because the particles are both homogeneous and heterogeneous.
FAQs on Experiment For Class 9 Chemistry Solution Colloids Suspension
1. What are the most frequently asked 3-mark questions on Solutions, Colloids, and Suspensions for the CBSE Class 9 exam (2025-26)?
Based on previous board trends and the importance of concepts, some expected 3-mark questions are:
- Differentiating between a true solution, colloid, and suspension based on particle size, stability, and visibility.
- Explaining the Tyndall effect with a labelled diagram and giving two examples of mixtures that exhibit it.
- Listing three distinct properties of suspensions with relevant examples like chalk in water or muddy water.
- Defining solubility and explaining how temperature affects the solubility of a solid in a liquid.
2. How can one experimentally distinguish between a true solution, a colloid, and a suspension? Why is this a critical concept for exams?
You can distinguish them using two key experimental tests:
- Filtration Test: When passed through filter paper, the components of a true solution cannot be separated. The particles of a colloid also pass through. However, the particles of a suspension are large enough to be left behind on the filter paper.
- Tyndall Effect Test: When a beam of light is passed through the mixtures, it is not visible in a true solution because the particles are too small to scatter light. In a colloid, the path of light becomes visible (the Tyndall effect) due to the scattering by colloidal particles. In an unstable suspension, the effect might be visible initially but disappears as particles settle down.
This concept is critical because it tests your understanding of the fundamental properties of mixtures, which is a core topic in the 'Is Matter Around Us Pure' chapter.
3. What are the key properties to differentiate between a true solution, a colloid, and a suspension?
The primary differences, which are important for exam questions, are:
- Particle Size: True solutions have particles smaller than 1 nm. Colloids have particle sizes between 1 nm and 1000 nm. Suspensions have particles larger than 1000 nm.
- Appearance: True solutions are transparent. Colloids are generally translucent. Suspensions are opaque.
- Stability: True solutions and colloids are stable, meaning their particles do not settle down when left undisturbed. Suspensions are unstable, and their solute particles settle down over time.
- Tyndall Effect: True solutions do not show it, colloids do, and suspensions may show it temporarily.
4. Why is milk considered a colloid and not a true solution? Identify its dispersed phase and dispersion medium.
Milk is considered a colloid because it is not a uniform mixture at the molecular level. It consists of tiny globules of fat and protein that are dispersed, but not dissolved, in water. These particles are large enough to scatter light (making milk opaque) but small enough to not settle down due to gravity, which are hallmark properties of a colloid.
- Dispersed Phase: The component present in smaller proportion, which is liquid fat globules.
- Dispersion Medium: The component in which the dispersed phase is suspended, which is water.
This type of colloid, where a liquid is dispersed in another liquid, is specifically called an emulsion.
5. What are some expected Multiple Choice Questions (MCQs) from the topic of Solutions, Colloids, and Suspensions?
For the Class 9 exam, you can expect MCQs that test your quick recall of concepts. For example:
- Which of the following will show the Tyndall effect? (a) Salt solution (b) Starch solution (c) Sugar solution (d) Copper sulphate solution. (Answer: b)
- A mixture of chalk and water is an example of a: (a) Solution (b) Colloid (c) Suspension (d) Saturated solution. (Answer: c)
- The particles of which mixture can be seen with the naked eye? (a) Colloid (b) True Solution (c) Suspension (d) All of the above. (Answer: c)
6. How can you prepare a saturated solution? What is an important question related to this concept?
To prepare a saturated solution at a given temperature, you take a fixed amount of a solvent (like water) and start dissolving a solute (like salt) in it while stirring. You continue adding the solute until no more of it dissolves and it starts to settle at the bottom. The clear liquid above the settled solute is the saturated solution.
An important related question is: 'What happens when a saturated solution is heated?' When heated, the solubility of the solid solute generally increases, allowing you to dissolve more solute in it. If this solution is then cooled slowly without disturbance, it becomes a supersaturated solution.
7. What are the different types of colloids based on their dispersed phase and dispersion medium, as per the CBSE Class 9 syllabus?
Several types of colloids are important for the exam. The key ones to remember with examples are:
- Sol: A solid dispersed in a liquid (e.g., Paint, Starch solution).
- Gel: A liquid dispersed in a solid (e.g., Jelly, Cheese, Butter).
- Emulsion: A liquid dispersed in another liquid (e.g., Milk, Face cream).
- Aerosol: A solid or liquid dispersed in a gas (e.g., Smoke - solid in gas; Fog/Mist - liquid in gas).
- Foam: A gas dispersed in a liquid (e.g., Shaving cream, Whipped cream).











