Question

A scientist wants to make a solution of tribasic sodium phosphate, Na3PO4, for a laboratory experiment. How many grams of Na3PO4 will be needed to produce 725 mL of a solution that has a concentration of Na ions of 1.30 M

Answer 1

51.53 grams .

Step-by-step explanation:

Na₃PO₄ ⇄ 3Na⁺¹ + PO₄⁻³ .

1 mole 3 mole

725 mL of 1.3 M Na⁺ ions

= .725 x 1.3 moles of Na⁺ ions

= .9425 moles

3 mole of Na⁺ is formed by 1 mole of Na₃PO₄

.9425 mole of Na⁺ is formed by .9425/3 mole of Na₃PO₄

Na₃PO₄ needed = .9425/3 moles = .3142 moles

Molecular weight of Na₃PO₄ = 164

grams of Na₃PO₄ needed = .3142 x 164 = 51.53 grams .