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Is Matter Around Us Pure — Science STD 9 — Question

CBSE BoardEnglish MediumSTD 9ScienceIs Matter Around Us Pure5 Marks
Question
What is crystallisation? How can this technique be used to purify impure copper sulphate?
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Answer

Crystallization: Crystallization is the solidification of atoms or molecules into a highly structured form called a crystal. Usually, this refers to the slow precipitation of crystals from a solution of a substance. However, crystals can form from a pure melt or directly from deposition from the gas phase. Crystallization can also refer to the solid-liquid separation and purification technique in which mass transfer occurs from the liquid solution to a pure solid crystalline phase.

The impure copper sulfate can be purified by crystallization. In this process, a suitable solvent is used for dissolving the impure sample and is heated in a water bath. This mixture is allowed to stand. After a while we obtain the pure crystals.

The crystals which obtained are extremely pure and are obtained from the procedure of crystallization. The solution is made from the combination of impure copper sulfate and a suitable solute.


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