A student has prepared 150.0 mL of 2.25 M Na3PO4. How many moles of ions are present in the solution?

Answer 1

150.0 ml x 1 L/1000 ml = 0.1500 liters

2.25 M Na₃PO₄ = 2.25 moles Na₃PO₄/liter

0.1500 liters x 2.25 moles Na₃PO₄/liter = 0.3375 moles of Na₃PO₄ in the 150 ml of solution

Now to find moles of ions, we must recognize that 1 mole Na₃PO₄ produces 3 moles Na⁺ and 1 mol PO₄^3-

Thus, 4 moles of ions are produced from 1 mole of Na₃PO₄. So total moles of ions will be.....

0.3375 moles Na₃PO₄ x 4 moles ions/1 mol Na₃PO₄ = 1.35 moles of ions