Question

How will you prepare a saturated solution of copper sulphate in water at 50 degree C ? What will happen if this solution is allowed to cool

Answer 1

A saturated solution is a solution in which no more solute can be dissolve at given temperature. The addition of any more solute will result in the accumulation of that solute in the bottom of the container.
To prepare the saturated solution of CuSO4 at 50$°$C, take a measured volume of water(say 100 ml.) in beaker and warm it up to 50$°$C​. Then add CuSO₄ pinc by pinc at constant stirring and observe the point when no more CuSO₄ is dissolving in water. At that point the added pinc of CuSO₄ will appear at the bottom of beaker and your saturated solution is prepared.
On cooling, crystals(particles) of CuSO₄ separate from the solution. This is a separation technique is known as crystallisation.