Question 2
Why does simple distillation of well water need no special control of conditions?
The right answer is the one marked above.
Because the boiling points of the salts are very much higher than that of water. With a gap that size, nothing else is close enough to water to come over with it. Only the water vaporises and the salts stay in the flask.
When several components all vaporise at temperatures close to one another, this apparatus is not enough and fractional distillation has to be used instead.