#Filtration

#Experiments

#Chemistry

Key points

• Filtration is used to separate an insoluble solid from a pure liquid or a solution.

• Filtration usually involves a circle of filter paper folded to make a cone and placed into a filter funnel.

• The filtrate is the liquid which passes through the filter paper and the residue is the solid left on the filter paper.

  
  

When is filtration used?

• If a substance does not dissolve in a solvent, it is called insoluble. For example, sand does not dissolve in water, meaning it is insoluble.

• Filtration is the process of separating solids from liquids using filter paper.

• The process can be used to separate an insoluble solid, for example stone or sand grains from a liquid. The liquid could be a pure liquid, for example water, or it could be a solution, for example, salty water.

• When a mixture of sand and water is filtered:

• the sand stays behind in the filter paper, it becomes the residue.

• the water passes through the filter paper, it becomes the filtrate.

How does filtration work?

• The mixture is poured slowly into the filter paper

• The filter paper has lots of tiny holes in it, which are far too small to see.

• The particles of the liquid including any dissolved solutes will pass through the holes in the filter paper.

• If the liquid contains an insoluble solid made of large particles, these larger particles cannot pass through the holes in the filter paper.