In this lesson, learners will demonstrate an understanding of solutions, including solute, solvent, concentration, saturation, solubility, and the effect of temperature on solubility. Students will recognise and represent these concepts using real-life examples, observation-based activities, and scientific explanations.
Students will be able to:
Reference: NCERT Book Alignment
The lesson aligns with the NCERT Grade 8 Science Textbook, Chapter 9: The Amazing World of Solutes, Solvents, and Solutions.
Section 9.2: How Much Solute Can a Fixed Amount of Solvent Dissolve?
By the end of the lesson, students will be able to:
In this session, students will explore how substances dissolve, what makes a solution, and why some mixtures dissolve completely while others don’t. Through real-life examples such as Gulab jamun syrup, air as a gaseous solution, and salt-water experiments, students will gain practical and conceptual understanding of solubility, concentration, and temperature effects. The lesson will utilise visual aids, simple demonstrations, and interactive questioning to build strong scientific reasoning.
| Title | Approximate Duration | Procedure | Reference Material |
|---|---|---|---|
| Engage | 5 | Show images: sugar in water, sand in water, Gulab jamun syrup, and air composition. Ask: “Have you ever wondered why sugar and salt disappears in water, but sand doesn’t? Or why does hot water dissolve more sugar than cold water?” Spark curiosity by comparing mixtures that dissolve vs those that don’t. | Slides |
| Explore | 10 | Ask: Why does sugar dissolve so well in hot water when making tea? But not as much in cold water? | Slides |
| Explain | 10 | Open the VR Link and explain the topic given below:
| Slides and Virtual Lab |
| Evaluate | 10 | Students will attempt the Self Evaluation task on LMS | Virtual Lab |
| Extend | 5 | Discuss real-life applications: 1.Where do you see solutions in daily life? (tea, perfumes, soft drinks, sea water, air) 2.Why do chefs heat water before adding sugar to make syrup? 3.If you cool down a hot saturated sugar solution, what will happen? | Slides |
In this lesson, students will learn about solutions and how solutes dissolve in solvents to form uniform mixtures. Through simple demonstrations, real-life examples, and hands-on activities, students will explore how different substances dissolve, what makes a solution saturated or unsaturated, and how temperature affects solubility. This helps students understand the mixtures they encounter every day—like air, juices, syrups, and water.
Introduction: Why learn about solutions?
Why learn about solutions?
Have you ever wondered why sugar disappears in water, but salt doesn’t? Or why does hot water dissolve more sugar than cold water?
Understanding this helps us know:
For example, when making Gulab Jamun syrup (chashni), a large amount of sugar dissolves in a small amount of water, demonstrating the power of solubility.
What is a Solution?
A solution is a uniform mixture of two or more substances.
Key Components:
Simple Example:
Salt (solute) + Water (solvent) → Salt solution (uniform mixture)
Special Case:
In the air, nitrogen acts as the solvent because it is the most abundant gas.
Steps / Process / Rules
Step 1: Add solute to solvent.
Step 2: Stir or shake to help particles mix.
Step 3: Solute spreads evenly → solution formed.
Solved Example
Which is more concentrated?
Answer: B is more concentrated because there is more solute in less solvent.
Visual Representation
Diagram Examples (Describe for students):
What happens to the undissolved baking soda? You will observe that it has dissolved. Continue adding more baking soda while stirring at this temperature until some solid baking soda remains undissolved. Again, heat the contents further to 70°C while continuing to stir. What do you observe? The undissolved baking soda dissolves. What do you infer from this experiment? Answer: Water at 70°C dissolves more of the baking soda than at 50°C. It is assumed that, for most substances, solubility increases with temperature. It can also be concluded that a saturated solution becomes unsaturated at higher temperatures.
Applications / Why is it Useful?
This is the list of vocabulary terms used throughout the lesson.
This Virtual Lab helps students understand how solutes dissolve in solvents to form solutions. Through interactive tabs and simulations, learners explore solute–solvent behavior in a beaker. They will observe the difference between unsaturated and saturated solutions. The lab also demonstrates how heat affects solubility, making more solute dissolve at higher temperatures. By the end, students complete a quiz to check their understanding of all concepts learned.
1 Access the Virtual Lab using the provided link.
2 Open the Navigation Menu tab on the left side of the screen.
3 Select 1.1 – Introduction.
4 Click 1.2 – Solute, Solvent & Solution.
5 Select 1.3 – Saturated & Unsaturated Solution.
6 Click 1.4 – Effect of Heat.
7 After completing all tabs, click Quiz.
8 Review all results and complete the activity.