Separation of Substances: Methods and Mixtures

A mixture of sugar, water and rice can be separated by the process of filtration, which will separate rice from the mixture; followed by evaporation which will separate water from sugar, leaving sugar behind. 

Muddy water can be purified by the process of sedimentation, followed by using alum, which removes the lighter impurities also. This water then may be chlorinated to kill any bacteria and to get pure water. 

Chalk powder is insoluble and salt is soluble in water. So, we will dissolve both the substances in separate test tubes. The one which gets dissolved will be salt and the other which is insoluble is chalk powder. 

Tea leaves are separated from liquid by using a strainer or sieve and the process is known as filtration. 

Clear solution, filtrate and pure substances are all pure, but impurities are the substances which make things impure. 

Winnowing is a method by which particles of the same size can be separated easily. 

Components are the substances which make a mixture. Pulses can be separated from salt by sedimentation as pulses settle down at the bottom. Sand can be separated from stones by sieving. Butter can be separated from curd by churning and not decantation. 

Chalk powder is insoluble in water. Out of salt, sugar and baking powder, salt particles are the smallest in size and thus, get dissolved the fastest in water. 

The component which can be blown away by the wind has to be lighter. Out of grains, sand, stone and sawdust, only sawdust is the impurity which is lighter in weight and can easily be blown off by wind. 

<span style="font-size:10.0pt;font-family:Arial;mso-fareast-font-family:"Times" new="" roman";mso-bidi-font-family:arial;mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa="">Threshing is a process in which grains are beaten to separate them from stalks. To separate large quantities, farmers generally use bullocks to beat the grains. 

<span style="font-size:10.0pt;font-family:Arial;mso-fareast-font-family:"Times" new="" roman";mso-bidi-font-family:arial;mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa="">Sieving is the method in which a sieve or the strainer is used which has small holes. Only fine particles can pass through these holes, whereas the bigger ones stay in the sieve. 

Hand picking refers to the removal of stones by hands. As it involves manual processing, it is quite a tedious and slow process and can not be used at large scale in godowns. 

Churning refers to rotating a mixture at a high speed so that the lighter particles come at the surface and the heavier particles settle down. This method is used to separate cream from milk as cream being lighter comes to the surface and milk being heavier settles down. 

Evaporation is a process of conversion of liquid into vapours. Water gets evaporated, mud settles down and it is salt which is recovered by evaporation.  

Filtration is a process of separating dust particles from a liquid. The liquid left behind after filtration is known as filtrate. 

<span style="font-size:10.0pt;font-family:Arial;mso-fareast-font-family:"Times" new="" roman";mso-bidi-font-family:arial;mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa="">Salt water from sea can be obtained by evaporating the water which may occur naturally due to the sun's heat.  

Milk when heated gives off water in the form of vapours. When milk is heated with the vessel covered, then water vapours can be observed on the inner surface of the lid. 

<span style="font-size:10.0pt;font-family:Arial;mso-fareast-font-family:"Times" new="" roman";mso-bidi-font-family:arial;mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa="">Solute in lower quantity is dissolved in a solvent. The mixture of the two is known as solution. 

The solubility of any substance can be increased by increasing the temperature of the solution. 

Filtration is a process, which is used to separate a solid substance from the liquid. E.g. separating tea leaves from tea. 

Sugar or any solute gets dissolved quickly when the temperature is higher. As hot coffee, soup, and boiled milk are hot, so sugar will quickly dissolve in these. Iced tea being at lower temperature will take longer time to dissolve sugar. 

<span style="font-size:10.0pt;font-family:Arial;mso-fareast-font-family:"Times" new="" roman";mso-bidi-font-family:arial;mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa="">Water turns into vapors by absorbing heat from the atmosphere. The process is known as evaporation. 

Heterogeneous mixture is the one in which the solute and solvent can be seen separately as the two do not get dissolved e.g. a mixture of sand and water, sugar and sand, rice and water etc. 

<span style="font-size:10.0pt;font-family:Arial;mso-fareast-font-family:"Times" new="" roman";mso-bidi-font-family:arial;mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa="">Seeds can be separated from juice by the process of filtration, as juice being liquid will pass through the holes of a filter but seeds being bigger in size will not.