Question

How can I calculate the moles of ions in solutions?

Answer 1

Concentration is usually expressed as moles per cubic decimetre or moles per litre.

`c=n/v`

So `n=cv`

So to find the number of moles we multiply concentration by volume.

E.g how many moles of NaCl in `25cm^3` of a solution of concentration `2.0mol.dm^(-3)` ?

`n=cv=(25)/(1000)xx2=0.05mol`

Note I divide by 1000 to convert `cm^3` to `dm^3`.