What is Crystallisation? Video Lecture | Science Class 7

have you seen crystals of salts crystals
are made through a process of
crystallization let us try to make salt
crystals from a solution of salt for
this we need thread a saturated solution
of copper sulfate and copper sulfate
first we will make a supersaturated
solution of copper sulphate light the
spirit lamp place the copper sulphate
solution on the burner heat the mixture
now keep on adding copper sulphate till
no more salt is dissolved
fasten a thread on a support and suspend
it in an empty glass this thread will
act as a nucleation center in the
container
now remove the solution from the burner
pour the solution in the glass
leave the glass aside for a few days we
see salt crystals formed on the string
this happens because the solubility of
salt in water increases with temperature
of solution so more salt gets
accommodated in the solution than it
would have if water was at room
temperature this solution is called a
supersaturated solution the salt from
this supersaturated solution gets
precipitated out when the solution
returns to room temperature the salt
molecules that get precipitated out
start forming crystals at the nucleation
center which is the thread in this case
crystallization is the process of
formation of solid crystals of a
substance by precipitating it out from a
saturated solution why don't you try
making sugar crystals at home