# How do you determine the density of water vapor at different temperatures?

##### 1 Answer

Jun 18, 2018

see below

#### Explanation:

you can consider water vapor as an ideal gas , so you can write the ideal gases law

where

P= pressure

V= volum

n= number of mol (n= mass in g/ MM)

R= universal costant of ideal gases

T= temperatur in K

so you can write the ideal gases law in this way

density is mass divided volume

and riarranged the equation you have

where you can see that increasing temperature, d decreases.

Moreover as the MM of water (18g/mol) is less than MM of air (about 29 g/mol), vapor has a less density tthan air