What type of water is least dense?

1 Answer
Jun 28, 2017

Well, clearly, water vapor is the least dense... And we cannot just claim that without data. Consider the following.

#rho_(H_2O(s)) = "0.9167 g/mL"# at #0^@ "C"# and #"1 atm"#

#rho_(H_2O(l)) = "0.9970749 g/mL"# at #25^@ "C"# and #"1 atm"#

#rho_(H_2O(g)) = "0.0005883 g/mL"# at #100^@ "C"# and #"1 atm"#

Gases are thus much less dense than their respective liquids. Usually about a thousand-fold...