What is is the variable and experimenter chooses to change

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.

What is the mass of phosphorous in a 51-kg person

Explain how global warming could have affected yellowstone frog and salamander habitat's, resulting in changes in the populations of these species