Question

When substances such as sugar and table salt are dissolved in water, the freezing points of the new solutions are lower than the freezing point of water. Also, the more material dissolved, the lower the freezing point. The boiling points of these solutions, however, are higher than that of water.

Which of the followingsolutions would have the highest boiling point?

1) 5 liters of water
2) 5 grams of salt dissolved in 4 liters of water
3) 10 grams of salt dissolved in 3 liters of water
4) 15 grams of salt dissolved in 2 liters of water
5) 20 grams of salt dissolved in 1 liter of water

i really have no idea

Answer 1

See above.

Answer 2

Isn't change in boiling point
delta T = i*Kb*m
i = 2 for NaCl.
Kb stays a constant.
molality = m = moles/kg solvent.
It appears to me that the highest m will have the highest delta T. So which is the highest m.