Sand can be separated from water using filtration because sand particles are much larger than the tiny holes (pores) in a filter medium, such as filter paper.
Filtration is a common method used to separate insoluble solids from liquids. In the case of sand mixed with water, the sand does not dissolve; it remains suspended or settles at the bottom. This difference in solubility and, crucially, particle size makes filtration an effective separation technique.
Here's the core principle based on the provided information:
- Particle Size Difference: The reference highlights that filtration can also be used to separate sand and water because sand particles have quite a bigger size than the pores of the filter paper.
- Mechanism: When the sand-water mixture is poured through a filter paper (or similar filter medium), the larger sand particles are physically blocked by the filter paper's pores and remain on top. The smaller water molecules, however, can easily pass through the pores, collecting below as a clear liquid.
The Process of Separating Sand from Water by Filtration
Separating sand from water via filtration typically involves a few simple steps and basic equipment.
What You Need
- Funnel
- Filter paper (specifically designed for filtration)
- Container for the mixture (e.g., a beaker or flask)
- Container to collect the filtered water (e.g., a beaker or flask)
- The sand-water mixture
Steps for Filtration
- Prepare the Filter: Fold the filter paper into a cone shape and place it inside the funnel.
- Set Up: Position the funnel in the neck of the collection container.
- Pour: Carefully pour the sand-water mixture into the filter paper cone in the funnel.
- Observe: Watch as the water passes through the filter paper and collects in the container below. The sand particles will build up on the surface of the filter paper.
- Completion: Continue pouring until all the mixture has been filtered. You will be left with the sand on the filter paper and the separated water in the collection container.
Why It Works (Revisiting the Reference)
As stated in the reference, the method is effective specifically because: "sand particles have quite a bigger size than the pores of the filter paper". This fundamental difference in scale is what allows the filter medium to act as a sieve, trapping the sand while letting the water pass through. So, "when filtration is done, the sand particles remain on the filter paper while the water runs down."
Summary of Separation
Here's a quick overview:
| Component | Behavior During Filtration | Outcome |
|---|---|---|
| Sand | Trapped by filter paper pores due to size | Remains on filter |
| Water | Passes through filter paper pores | Collects below filter |
Filtration is a widely used technique in laboratories and industry for purifying liquids or separating solid particles from them. It's a simple yet effective application of physical separation based on particle size.
