indicating the total number of ions present in a solution

Question

Chemical Formula of Salt NaI

Cation Na+ 

Anion I-

What is the total number of ions in 1.0 L of a 1.0 mol/L solution 

Answer 1

If you have 1 liter of solution, and that solution contains 1.0 moles of sodium iodide (NaI), then it will contain 

1 mole of Na⁺ ions, and 1 mole of I^- ions.  That is a total of 2 moles of ions.

To find the NUMBER of ions, you multiply 2 moles of ions x Avogadro's number (6.022x1023 ions/mole) = Answer.