500 mL of a 0.4 M sodium nitrate contains ________ moles of sodium ions and ________ moles of nitrate ions.

Question

Quizplus · Accepted Answer

The solution contains 0.2 moles of sodium ions and 0.2 moles of nitrate ions because the concentration (0.4 M) refers to the sodium nitrate as a whole. Since the volume is 500 mL (or 0.5 L), the amount of sodium nitrate is 0.4 M * 0.5 L = 0.2 moles. Sodium nitrate dissociates into one sodium ion and one nitrate ion for each formula unit, so there are also 0.2 moles of each ion.

500 ML of a 0