Answer
0.25 mol/L Na+ and 0.25 mol/L NO3-
Work Step by Step
NaNO3 will break up into Na+ and NO3-. There is 1 mole of Na+ and 1 mole of NO3- per each mole of NaNO3. Therefore, if we have 0.25 M or 0.25 mol/L of NaNO3 then we will also have 0.25 mol/L Na+ and 0/25 mol/L NO3-.