Calculate the sodium ion (Na+) concentration for a 0.387 M Na3PO4 solution.\

Answer 1

Hi Madeline!

Happy to answer this problem for you. There are a couple of concepts you need to recognize before doing the calculations to answer this.

1. Sodium phosphate (Na₃PO₄) is a soluble ionic compound, meaning that when put into water, it will dissolve and dissociate into its respective ions, Na⁺ and PO₄^3- (a polyatomic ion).
2. You can write a dissociation reaction, which depicts what is going on in solution when you put the sodium phosphate into water to make a solution.
3. It would look like this: Na₃PO₄ --> 3Na⁺ + PO₄^3-
4. To be able to write this dissociation reaction, you must know the charges of sodium (+1) and phosphate (-3) ions to be able to properly balance the reaction.
5. You can use this dissociation reaction and your stoichiometry skills to calculate the concentration of Na⁺ ions in solution.

Now, using the dissociation reaction, use your given value to convert to the concentration of Na⁺. For every 1 Na₃PO₄, there are 3 Na⁺. So:

(0.387mol Na₃PO₄/L) * (3 mol Na⁺/1 mol Na₃PO4) = 1.16M Na⁺

Hope this helps!

Chris