Question

Calculate the number of grams of sodium in 9.1 g

of each of the following sodium-containing food additives.

Na3PO4
(sodium phosphate)
Express your answer using two significant figures.

Answer 1

Hi first you want to convert your grams of sodium phosphate into moles.

9.1 g Na3PO4 x 1 mole/ 163.94 grams = 0.056 moles of Na3PO4

Then we want to convert this to the amount of sodium by multiplying it to the ratio of the compound

0.056 moles Na3PO4 x 3Na/ 1 NaPO4 = approximately 0.17 moles of Na

Now that we have the amount of moles of sodium, let’s convert it to grams

0.17 moles of Na x 22.99 grams of Na/ 1 mole = 3.9 grams of Sodium in Na3PO4


Answer is 3.9 grams.