Test: Separation of Substances

The method of separation used to separate stone from rice is handpicking.

• Winnowing is the method in which heavier components of the mixture are separated from the lighter substances with the help of wind.
• This method is used for separating grains from husk after the process of threshing.

• Chalk powder is a carbonate compound, insoluble in water.
• Because of this property of chalk powder, it is easy to separate it from water.
• The mixture containing chalk powder and water is allowed to get filtered.
• (Filter paper can be used for filtration) After filtration, the retentate obtained is chalk and the filtrate obtained is water without chalk.
• The retentate is allowed to get dried and hence, chalk is obtained in powder form.

A homogeneous mixture is a mixture in which the composition is uniform throughout the mixture. The saltwater is homogeneous because the dissolved salt is evenly distributed throughout the entire saltwater sample.
OR
A solution of salt and water is a homogenous solution as no separate boundary is formed.

• Difference in weight is the properties used to separate two solids from a mixture by winnowing.
• Husk or dirt particles can be separated by winnowing method. It is used to separate the heavier and lighter components of a mixture by wind or by blowing air.
• In this method, the mixture of husk and seeds of grain are take in plate and are made to fall down from a height up to our shoulders.

Most of the substances that we see around us are mixture of two or more substances.

Solids, liquids and gases all dissolves in water depending upon the type of the solute.

Suspended particles in water can be settled down by using alum as dust particles in water settled faster.

The process by which the unwanted solid particles are removed from the liquid is called as filtration.

Boiling point of pure water is 100⁰C.