How many moles of ions are released when this sample is dissolved in water?
3.55*10^18 formula units of Ba(OH)2*8H2O?
So far I know to divide this by avogadro's number (/6.022*10^23) which equals .590*10^-5 mol. Don't know what to do from here. Please help!
Ok, then for each of those formula units, you get one barium+2 and two hydroxide-1 ions, or three ions for each formula unit.
Multilply your answer by 3
Ok, so 1.77*10^-5 mol ions?
To determine the number of moles of ions released when the given sample of Ba(OH)2*8H2O is dissolved in water, you need to know how many ions are present per formula unit of the compound.
The formula of Ba(OH)2*8H2O indicates that each formula unit contains one barium ion (Ba^2+) and two hydroxide ions (OH^-). Since there are eight water molecules (H2O), we can ignore them for this calculation since they do not release any ions.
Therefore, when Ba(OH)2*8H2O is dissolved in water, each formula unit releases three ions (one Ba^2+ ion and two OH^- ions).
To calculate the total number of moles of ions released, you already correctly divided the number of formula units (3.55*10^18) by Avogadro's number (6.022*10^23). This gave you the value of 0.590*10^-5 mol, which represents the number of moles of formula units.
To determine the moles of ions, you need to multiply this value by the number of ions released per formula unit. In this case, since each formula unit releases three ions, you can multiply 0.590*10^-5 mol by 3:
0.590*10^-5 mol * 3 = 1.770*10^-5 mol of ions
Therefore, the number of moles of ions released when 3.55*10^18 formula units of Ba(OH)2*8H2O are dissolved in water is 1.770*10^-5 mol.