To separate a mixture containing salt water and insoluble chalk, you can utilize a two-step process based on the physical properties of the substances involved.
The mixture essentially consists of three components: dissolved salt, water, and solid chalk particles. The separation relies on the fact that salt dissolves in water (forming a homogeneous solution) while chalk does not (remaining as a heterogeneous suspension).
Understanding the Components
As noted in the reference, putting a mixture of common salt and chalk powder in water allows for separation. Common salt dissolves uniformly with water, creating a homogeneous mixture (salt water). Chalk powder, however, remains heterogeneous, meaning it does not dissolve and is suspended in the liquid. This difference in solubility is key to the separation process.
The Separation Steps
The separation process involves first isolating the insoluble solid (chalk) from the liquid (salt water), and then separating the dissolved solid (salt) from the liquid (water).
Step 1: Removing the Insoluble Chalk
The first step is to separate the solid chalk particles from the salt water. Since chalk is insoluble and remains as a suspension, this can be achieved through filtration.
- Process: Pour the mixture through a filter medium, such as filter paper placed in a funnel.
- Mechanism: The salt water passes through the pores of the filter paper, while the larger, solid chalk particles are trapped on the filter paper.
- Result: The liquid collected below the filter is called the filtrate (which is salt water), and the solid collected on the filter paper is the residue (which is the chalk).
According to the reference, chalk powder is heterogeneous so it could be separated by the filtration method by using filter paper. This confirms filtration is the correct method for removing the insoluble chalk.
Step 2: Separating Salt from Water
After filtration, you are left with salt water (the filtrate). To separate the dissolved salt from the water, a different method is needed, typically one that involves changing the state of the water.
- Process: A common method is evaporation. Heat the salt water in an open container.
- Mechanism: The water will turn into water vapor and escape into the atmosphere, leaving the dissolved salt behind as a solid residue.
- Result: The water evaporates, and solid salt crystals are left in the container.
Alternatively, if you wish to collect both the salt and the water, distillation can be used.
Summary of Separation Methods
Here is a simple overview of the steps:
| Step | Method | What it Separates | Result |
|---|---|---|---|
| 1: Remove Insoluble Solid | Filtration | Insoluble Chalk from Salt Water | Chalk (residue), Salt Water (filtrate) |
| 2: Separate Dissolved Solid | Evaporation | Salt from Water | Solid Salt, Water Vapor |
By following these steps, you can effectively separate the chalk, salt, and water from the original mixture.
