Imagine you wanted to separate the components of the river water:

Question

a. What properties of these substances would be useful to separate them.
b. What techniques could you use to separate the components?
c. Explain your choice/s.

Answer 1

a. To separate the components of river water, the following properties of the substances would be useful:

1. Density: Different substances have different densities, which can be used as a basis for separation.
2. Particle size: The size of the particles in the river water might vary from large to small, making it possible to separate them based on this property.
3. Solubility: Some substances in river water may be soluble whereas others may be insoluble, which can be a factor for separation.
4. Vapor pressure and boiling point: Components in river water may have different boiling points, allowing for separation based on this property.
5. Magnetic properties: If some components are magnetic, they can be separated using a magnetic force.

b. The following techniques could be used to separate the components of river water:

1. Filtration: This is a mechanical or physical process that involves passing the water through a filter to separate solid particles based on their size.
2. Evaporation: This process involves heating the water, causing the liquid to evaporate, leaving behind any solid components.
3. Distillation: This process involves boiling the river water and then condensing the vapor in a separate container. This would separate the components based on their boiling points.
4. Sedimentation and decantation: This involves allowing solid particles to settle at the bottom of a container and then pouring off the liquid layer.
5. Centrifugation: This process involves spinning a sample of river water at high speeds to separate substances based on their densities.
6. Magnetic separation: If any components are magnetic, they can be separated by applying a magnetic force.

c. The choice of technique depends on the specific properties of the substances in the river water and the desired level of separation.

1. Filtration would be the best choice if the main goal is to remove large solid particles from the water, without altering the soluble components.
2. Evaporation would be suitable for isolating dissolved solids from the water but would not separate the different dissolved components from each other.
3. Distillation would be a good choice for separating components based on their boiling points and obtaining pure water.
4. Sedimentation and decantation would be suitable if the components have different densities and can be easily separated by allowing them to settle.
5. Centrifugation would be useful for separating components based on their densities, especially when dealing with very small particles that may not settle quickly during sedimentation.
6. Magnetic separation should be used when one or more components are magnetic, allowing for easy separation from the rest of the components. This would not work for substances with no magnetism.