Explain Stractually for electrovalent compound

This is a characteristic of the elements in the periodic table that shows a pattern. it may increase or decrease across or down the table.

The boiling point of propanoic acid is higher than that of 1-butanol because: propanoic acid has a higher molecular weight than 1-butanol. propanoic acid is more soluble in water than 1-butanol. propanoic acid is a better hydrogen bond donor than 1-butanol. propanoic acid forms hydrogen bonded dimers and 1-butanol does not. 1-butanol forms hydrogen bonded dimers and propanoic acid does not.

Explain what happens at the saturation point when adding salt to water at room temperature.