which solution has the highest boiling point?

a. 1 mole of NaNO3 in 500 g of water
b. 1mole of NaNO3 in 1000g of water
c. 1mole of NaNo3 in 750g of water
d. 1mole of NaNo3 in 250 g of water

The boiling point of water is elevated by about 0.5 degree for a 1 molal solution. The formula for this is
delta T = Kb*i* molality.
K is a constant which is about 0.5, i is the number of dissolved particles, and m is the molality.
For this problem you need to determine the number of dissolved particles, that is, i in the formula.
Since K is the same for all of them, that can be ignored.
delta T = i*m
See which one is the largest delta T.

so do i take the answer of NaNo3 which is 84 and the n devide it but the 500, 100, 750 and 250

No, you look at the molality of each.
molaltiy is defined as # mols/kg solvent.
The first one is
1mol/0.5 kg = 2m
The second one is
1 mol/1 kg = 1m
etc. The one with the largest m will be the one with the highest boiling point.

ok thanks i think i got it now

So the answer is A. 1 mole of NaNO3 in 500 g of water

You're welcome! I'm glad I could help. If you have any more questions, feel free to ask!

You're welcome! I'm glad I could help. If you have any more questions, feel free to ask.