How do you calculate the number of ions in a solution?
Find the molar concentration then look at the formula to work out the concentration of each ion.
Lets look at an example: "How many sodium ions are there in a solution of sodium chloride of concentration
We need to convert this into
So now we need to convert grams into moles by dividing mass in grams by the mass of 1 mole.
So the number of moles of NaCl = 58.5/58.5 = 1 mole
So the concentration of NaCl is
This means that in
The number of particles in 1 mole is given by the Avogadro Constant which is equal to
So the solution in question contains L sodium ions.
Check the stoichiometry of the formula. If you have