In yesterday’s CUBE ChatShaala, Seethalakshmi try to explain the difference between Diffusion and Osmosis, However it made hard difficult to expressing it . Just like Seethalakshmi, students used to get confused and overwhelmed to understand the concept . We make them understand by using Everyday Example . This helps them to understand with context and can related to thier every day activity. For context :
Have you ever wondered how water knows where to go? Or why salty chips can shrivel up a slice of cucumber? Let’s explore the fascinating world of diffusion, osmosis, and tonic solutions — all happening quietly around (and inside) us every moment!
Diffusion: The Dance of Molecules
Diffusion is the natural movement of particles (like gases or solutes) from a place where they are crowded (high concentration) to where they’re fewer (low concentration).
No extra energy needed — it’s all passive!
Everyday Example:
- Perfume spreading in a room.
- Sugar dissolving evenly in water.
In Cells:
- Oxygen diffusing into our blood from the lungs.
Osmosis: Water’s Secret Superpower
Osmosis is a special type of diffusion — it’s all about water!
Water moves across a semi-permeable membrane (like a cell membrane) from a region of low solute concentration (more water) to high solute concentration (less water), trying to “balance” both sides.
Everyday Example:
- Soaked raisins swell up as water moves in.
- Wilted vegetables getting crisp in plain water.
In Cells:
- Water entering plant root cells from the soil.
Isotonic, Hypotonic, and Hypertonic: Tonicity Explained!
Tonicity tells us how water moves when cells are placed in different solutions. It’s all about solute concentration outside vs. inside the cell.
Isotonic Solution (Equal Concentration)
- No net movement of water.
- Cell stays the same size.
Example:
- Saline used in IV drips (0.9% NaCl) — safe for blood cells.
Hypotonic Solution (Less Solute Outside)
- Water moves into the cell.
- Cell swells and may burst (in animal cells).
Example:
- Pure water around a red blood cell — the cell may burst!
- Soaked dry fruits puff up in water.
Hypertonic Solution (More Solute Outside)
- Water moves out of the cell.
- Cell shrinks (plasmolysis in plant cells).
Example:
- Salt sprinkled on cucumber — draws out water.
- Honey used on wounds — pulls out water from bacteria!
Summary Table:
Concept | What Moves? | Direction | Real-Life Example |
---|---|---|---|
Diffusion | Molecules | High → Low | Smell of perfume in a room |
Osmosis | Water | High → Low (of water) | Soaked raisins swelling |
Isotonic | – | No net water movement | IV saline solution |
Hypotonic | Water | Into the cell | Fresh water around red blood cells |
Hypertonic | Water | Out of the cell | Salting vegetables before cooking |

Why It Matters:
These tiny molecular movements keep our bodies balanced, plants upright, and food science interesting!
Whether it’s staying hydrated, making pickles, or saving lives with IV fluids — osmosis and diffusion are quietly shaping our world.
Now that you know the secret behind “The Great Water Escape,” can you spot osmosis in your kitchen or garden today?
@Arunan @KiranKalakotiR @2020ugchsncnseethala @Enas_188 and others.