# How many moles of Ca2+ are present in 5.67 moles of calcium phosphate? I"m not sure how to approach the problem.

There are $17.01$ moles of calcium 2+ ions in $5.67$ moles of calcium phosphate.
The chemical formula for calcium phosphate is "Ca"_3"(PO"_4)_2. This means that in one mole of calcium phosphate, there are three calcium ions and two phosphate ions.
To determine the number of moles of ${\text{Ca}}^{2 +}$ ions that are in $5.67$ moles of "Ca"_3"(PO"_4)_2, do the following:
$5.67 \text{mol Ca"""_3("PO"_4)_2xx(3 "mol Ca"^(2+))/("1 mol Ca"""_3("PO"_4)_2) = 17.01 "mol Ca"^(2+)}$