Substances present in Soil in Soil – Our Life – Class 7 Science Experiment
Chapter Name: Soil – Our Life
Activity Name: Substances present in Soil in Soil – Our Life
Activity Description:
This experiment aims to identify the substances present in soil by extracting them using rainwater or distilled water. The soil-water mixture is then heated to evaporate the water and observe the remaining substances.
Required Items:
- Beaker
- Soil
- Rainwater or distilled water
- Twig
- Boiling tube
- Candle flame
- Blue and red litmus paper
Step by Step Procedure:
- Fill a beaker half full with soil.
- Pour enough rainwater or distilled water over the soil to fill the beaker three-fourths full.
- Stir the soil and water mixture using a twig.
- Allow the solution to stand for some time until the soil settles down.
- Carefully drain out the water from the beaker into a boiling tube.
- Fill the boiling tube half full with the drained water.
- Heat the boiling tube over a candle flame.
- Continue heating until only a fourth of the water remains in the boiling tube.
Experiment Observations:
- Note the color of the water after heating.
- Test the water using blue and red litmus paper to determine if it is acidic or basic. Record the results in the table.
Precautions:
- Be cautious while handling the candle flame to avoid accidents.
- Ensure the draining of water from the beaker is done carefully to avoid losing any extracted substances.
- Use appropriate safety measures when heating the boiling tube.
Lesson Learnt from Experiment:
The experiment demonstrates that soils contain various minerals, including salts of sodium, calcium, magnesium, and potassium chlorides, sulphates, and carbonates. It also highlights the impact of highly acidic soil on plant growth, as it can affect nutrient absorption efficiency.
