Which property of an unsaturated solution of sodium chloride in water remains the same when more water is added to the solution?
(1) density of the solution
(2) boiling point of the solution
(3) mass of sodium chloride in the solution
(4) percent by mass of water in the solution

Choice 3) The absolute mass of the sodium chloride itself will not change since only water is added but there will be a higher ratio of water to sodium chloride so any ratio-based property will change. Boiling point is including as being directly affected by the ratio of water to sodium chloride so this would also change when more water is added.

The answer would be

6because i no yea yea