Finding of heterogeneous mixtures- suspensions and colloids in Is Matter Pure – Class 9 Science Experiment

Chapter Name: Is Matter Pure

Activity Name: Finding of heterogeneous mixtures- suspensions and colloids in Is Matter Pure

Activity Description:

In this experiment, we will investigate two different substances, chalk powder and milk, to determine whether they form heterogeneous mixtures, specifically suspensions. We will observe the behavior of these substances when mixed with water, how the particles interact, and whether they settle over time.

Required Items:

1. Chalk powder
2. Milk
3. Water
4. Test tubes
5. Glass rod
6. Torch or laser beam

Step by Step Procedure:

1. Take a test tube and add some chalk powder to it.
2. In another test tube, take a few drops of milk.
3. Add water to both test tubes.
4. Stir the mixtures with a glass rod and observe whether the particles are visible in the mixtures. Determine if the mixtures are heterogeneous or homogeneous based on their appearance.

Experiment Observations:

1. We observe that the particles of chalk powder do not dissolve in water but remain suspended throughout the volume of the liquid.
2. The milk particles also do not dissolve but form a suspension in water.
3. The mixtures are heterogeneous as the solute particles do not dissolve, and they are visible to the naked eye.

Note down your observations in table format:

Precautions:

• Handle the glassware and chemicals with care to avoid accidents.
• Use a clean glass rod for stirring to prevent contamination of the mixtures.

Lesson Learnt from Experiment:

Through this experiment, we learned about heterogeneous mixtures, specifically suspensions. A suspension is a type of heterogeneous mixture in which the solute particles do not dissolve but remain suspended throughout the solvent. These suspended particles can scatter light and settle down over time if left undisturbed. Such mixtures have visible particles and are not transparent.