Question #ac64e

1 Answer
Dec 4, 2017

Answer:

Here's what I got.

Explanation:

Interestingly enough, the name sodium phosphate is actually used to describe a family of salts that contain sodium cations and phosphate anions in various ratios.

My guess is that you are supposed to treat "sodium phosphate" as trisodium phosphate, #"Na"_3"PO"_4#.

The idea here is that a formula unit of sodium phosphate, #"Na"_3"PO"_4#, contains

  • three sodium cations, #3 xx "Na"^(+)#
  • one phosphate anion, #1 xx "PO"_4^(3-)#

This, of course, implies that #1# mole of sodium phosphate will contain #3# moles of sodium cations and #1# mole of phosphate anions.

In other words, you have

  • #"no. of moles of Na"^(+) = 3 xx "no. of moles of Na"_3"PO"_4#
  • #"no. of moles of PO"_4^(3-) = "no. of moles of Na"_3"PO"_4#

Since you know that your sample contains #0.500# moles of sodium phosphate, you can say that it contains #1.50# moles of sodium cations and #0.500# moles of phosphate anions.