Concentration Question?

Question

What is the concentration, in moles per liter, when 1.5g NaI is dissolved in 250-mL solution of NaI (at. wts: Na=23.0, I=126.9)

Answer 1

Add the atomic weights. Divide this into 1.5 g. This will give you the number of moles of NaI. Then convert 250 mL to liters (0.250 L). Now divide 0.250 L into the number of moles you determined above:
[1.5 g/(23 g/mol + 126.9 g/mol)]/0.250 L = your answer
I hope this helps

Answer 2

Convert the mass of NaI into moles by dividing by its molar mass.

Then, divide the number of moles by the volume of the solution in Liters to get the molarity.

Answer 3

this will be the case only if u dissolve ur NaI in a pure solvent to get a 250ml solution (presumably what u actually mean).
if u want to dissolve NaI in a Nai solution, it all depends on the concentration of the NaI solution that u dissolve the stuff in.