water of crystallisation

hydrated ions

ions which are surrounded by water molecules

ion dipole forces

forces holding these hydrated ions together

Water of crystallisation refers to...

water molecules woven into a salt’s solid crystal lattice

hydrated salt

If a salt contains water of crystallisation

anhydrous salt

If a salt doesn’t contain water of crystallisation

How would we represent this hydrated salt?

CuSO₄.4H₂O

How would we represent this hydrated salt?

CuCl₂.2H₂O

We can turn a hydrated salt into an anhydrous salt by...

heating it vigorously

It’s virtually impossible to turn a sample of an anhydrous salt into a hydrated salt in one step because…

it requires adding an exact amount of water

a small amount of the anhydrous salt will dissolve in the water

we can’t ensure that the water added will be distributed evenly throughout the sample

Anhydrous copper sulfate can be added to a sample of liquid to test for water.

If the copper sulfate dissolves in the liquid to form a blue solution or turns into a blue solid, this means…

there is water in the sample

Anhydrous copper sulfate can be added to a sample of liquid to test for water.

If the copper sulfate remains as a white powder, this means…

there isn’t water in the sample

Anhydrous salts are mainly used…

to test for water

to remove water from a reaction mixture

to remove water from a solvent