Copper Sulphate Crystals

Copper sulphate crystals.

Evaporating dish with copper sulphate was weighted Mass 2 = 54.81g.

Using dropping pipette few drops of the solution was added onto the cavity on the microscope slide and observed. Crystals were seen, as the solution temperature was going down, it went more solid, and crystals were more close to one another. When the temperature cooled down, the solid hydrated copper sulphate crystals were formed.

Mass 2 (evaporating dish with hydrated copper sulphate) – 54.81g

Mass 3 (evaporating dish with anhydrous copper sulphate) – 51.46g

According to the moles, we can count the ratio of:

We can see that by heating blue hydrated copper II sulphate water was lost by vapour, as the mass decreased after heating it by 3.35g, and colour changed to white. It was endothermic reaction, as heat was required for the reaction to happen. After adding it back to water under the high temperature it dissolved, went back to blue colour and crystals where seen through the microscope. This shows that it is reversible reaction.

Over all, we could say that water is necessary for crystal formation. As well as the bonds of crystallised water are easily broken under the high temperature.