Phosphate standards used to generate the calibration curve

Question

Phosphate standards used to generate the calibration curve are usually made by first preparing a stock solution of known concentration, then diluting it to the required concentration.

First prepare a stock solution that is 1.00 x 10^-2 M in phosphate ion. How many g of Na₃PO₄ would you add to a 50 mL volumetric flask to to prepare this solution?

Mass Na₃PO₄: ______g.

What is this concentration in ppm of phosphate? (That is as PO₄^3-, not Na₃PO₄).

PO₄^3- concentration: _____ppm.