a scientist wants to make a solution of tribasic sodium phosphate ,Na3PO4, for an experiment. how many grams of Na3PO4 will be needed to produce 750 mL of a solution that has a concentration of Na+ ions of 1.30M

Answer 1

The easiest way is to solve for grams Na3PO4 needed, then divide by 3 since there are 3 moles Na^+ per mole Na3PO4.

M = moles/L
1.3 M = moles/0.750 L
moles = 1.3 x 0.750 = ??
??/3 = moles Na3PO4 L needed for 1.3 M in Na^+.
Then moles = grams/molar mass.
You have moles and molar mass. Calcualte grams.

Answer 2

An experiment in your laboratory requires 500 mL of a .0200 M solution of Na2CO3. You are given solid Na2CO3, distilled water and a 500 mL volumetric flask Describe how to prepare the required solution showing all calculations and describing each step appropriately.