Which of the following solutions of strong electrolytes contains the largest number of ions?

Question

50.0 mL of .175 M NaOH, 100.0 mL of .250 M BaCl₂, or 250.0 mL of .050 M Na₃PO_4?

I would really appreciate if you could explain what to do in order to determine which solution contains the most ions--I did it a certain way and got that BaCl₂ would have the most ions, but I'm not sure I did it right. Please help and thank you!!

Answer 1

The largest NUMBER of ions or the largest CONCENTRATION of ions ?

50 ml of 0.175 M NaOH: 0.05 L x 0.175 mol/L = 0.00875 moles x 2 moles ions/mole NaOH= 0.0175 moles ions

100 ml of 0.25 M BaCl₂ : 0.1 L x 0.25 mol/L = 0.025 moles x 3 moles ions/mole BaCl₂ = 0.075 moles ions

250 ml of 0.05 M Na₃PO₄ : 0.25 L x 0.05 mol/L = 0.0225 moles x 4 moles ions/moke Na₃PO₄ = 0.05 moles of ions.

So, the one with the largest NUMBER OF IONS would be the BaCl₂ solution.

NOTE: Please see my more complete answer here: https://www.wyzant.com/resources/answers/705786/calculate-the-concentrations-of-each-ion-remaining-in-solution-after-the-pr

Answer 2

Valesia

I believe you are correct.

I calculated the number of milimoles of each compound by multiplying the Molarity by the volume.

NaOH was 8.75

BaCl2 is 25

Na3PO4 12,5

For each, then, I multiplied the milimoles by the largest number of ions in the formula

NaOH - 1

BaCl2 - 2 Cl

Na3PO4 3 Na

BaCl2 has 50 total ions, Na3PO4 has 37.5 and NaOH has 8.75