Class 9 Science- Chapter 1- Matter In Our Surroundings – Activity 1.4: Adding Ink and Honey to Water to Observe Diffusion and Intermixing

Activity 1.4: Adding Ink and Honey to Water to Observe Diffusion and Intermixing

Objective

To demonstrate how particles of different substances intermix on their own (diffusion) when added to water. The activity uses ink and honey to observe how substances spread and mix in a liquid.

Materials Needed

• Two glasses or beakers.
• Water.
• A drop of blue or red ink.
• A drop of honey.

Steps to Perform the Activity

1. Fill two glasses or beakers with water.
2. Carefully add one drop of ink to the first glass along the side of the beaker.
3. Add one drop of honey to the second glass in the same manner.
4. Do not stir either glass and leave them undisturbed for a few hours or a day.
5. Observe the spreading of ink and honey over time.

Observations

• Ink in Water:
  Immediately after adding the ink, it begins to spread through the water. Over time, the entire water turns a uniform color, showing complete mixing.
• Honey in Water:
  The honey initially sinks to the bottom as it is denser than water. Gradually, it dissolves and spreads throughout the water, forming a uniform mixture.

Also Check – Chapter 1 -MATTER IN OUR SURROUNDINGS -Class 9 – Simplified notes

Concepts Behind the Activity

1. Diffusion in Liquids:
   Diffusion is the process by which particles of one substance move from an area of higher concentration to an area of lower concentration.
   • Ink Example: The ink particles diffuse quickly and mix with water because they are lighter and spread through the spaces between water particles.
   • Honey Example: Honey, being denser, takes longer to diffuse. Its particles gradually spread through water, showing the same principle.
2. Effect of Particle Motion:
   The particles in water are always in motion. This motion allows ink or honey particles to collide with water particles and spread evenly, forming a homogeneous mixture.
3. No Stirring Required:
   Diffusion occurs naturally due to the movement of particles. No external force, like stirring, is needed for this process.

Learning Outcomes

1. Diffusion Happens in Liquids:
   The activity demonstrates how particles of a substance, such as ink or honey, mix with liquid particles on their own through diffusion.
2. Density Affects Diffusion:
   Honey, being denser than water, takes longer to spread compared to ink, which diffuses faster due to its lighter composition.
3. Intermixing of Particles:
   The particles of ink or honey occupy the spaces between water particles, highlighting the intermixing nature of matter.

Applications of Diffusion in Liquids

• Preparation of solutions like tea, coffee, or lemonade.
• Dissolving medicines in water for consumption.
• Mixing of food coloring or flavoring agents in cooking.

Intext and additional Question Answers on Activity Activity Activity Activity 1.4: Adding Ink and Honey to Water to Observe Diffusion and Intermixing

Question 1: What do you observe immediately after adding the ink drop?
The ink spreads outward in patterns as it starts mixing with the water. This happens because the ink particles diffuse into the spaces between the water molecules.

Question 2: What do you observe after adding a drop of honey?
The honey sinks to the bottom due to its higher density and then begins to dissolve slowly, spreading gradually throughout the water.

Question 3: How many hours or days does it take for the color of ink to spread evenly throughout the water?
The ink spreads uniformly within a few minutes to hours, depending on factors like temperature and motion (stirring or still water).

Additional Question: Why does honey dissolve slower than ink?
Honey dissolves slower because its molecules are larger and denser than ink particles. Additionally, the intermolecular forces in honey are stronger, requiring more time for the water molecules to break them apart and allow diffusion.

Conclusion

This activity shows that diffusion occurs in liquids when particles of one substance intermix with particles of another. The behavior of ink and honey demonstrates how different substances diffuse based on their properties, such as density and particle motion. This helps us understand the natural process of intermixing in liquids without external force.