A scientist wants to make a solution of potassium phosphate, K3PO4 for a lab experiment. How many grams of K3PO4 will be needed to produce 575ml of a solution that has a concentration of K+ ions of 1.4M.

Answer 1

K3PO4 ==> 3K^+ + PO4^3-
You can see that 1 mol K3PO4 produces 3 moles K^+ ions.
So if (K^+) = 1.4M, then (K3PO4) must be what? (1/3)*1.4 = ??(K3PO4).

How many moles K3PO4 do you need? M x L = moles.
moles = grams/molar mass. Solve for grams.