Using specimens A, B (WATER), C (SODIUM CARBONATE).and D, carry out an experiment to show that soil is made up of different particle sizes
(a) (i) Describe the procedure used in concting the experiment
(ii) State your observations and results
(b) State one function of each of specimens B and specimen C in the experiment
(c) State three precautions taken in carrying out the experiment.
Explanation
(a) (i) Description of the procedure used ln conducting the experiment
- Some quantity of soil was weighed
- The soil was put in a 250cm measuring cylinder
- Some water was added to the soil in the cylinder to submerge the soil
- A little quantity of sodium carbonate was added into the cylinder
- A hand was placed over the opening of the cylinder
- The cylinder was then placed on a flat level bench for at least an hour to allow contents settle
(ii) Observations and results -
- The bigger gravels settled first
- The soil fractions settled in layers o
- Followed by sand
- And silt and
- Clay
- Colloids remained in suspension
- Humus and organic materials were seen floating
- Depth of each layer was read from the marks on the cylinder.
(b) Function of Specimen B (water) and Specimen C (sodium carbonate) in the experiment
Water (Specimen)
- Provides a medium for dispersing the soil and dissolve the chemical
- Enhances the differential settling of materials
Sodium Carbonate (Specimen C)
- Enhances complete dispersal of soil aggregates/faster
- Makes/renders the reading of the levels/layers easier
(c) Precautions to take in carrying out the experiment -
- Cover the opening of the cylinder well to prevent spillage when shaking
- Do not add too much sodium carbonate to the soil as that will reduce readability of layers
- Allow sufficient time for content to settle properly
- Place cylinder on a horizontal surface to ensure correct reading
- Avoid error of parallax when reading results
- Enough water should be added to the soil to allow free floatation and sedimentation, otherwise, the experiment will not work.