# What is the ratio of actual water vapor the air to the amount of water vapor needed to reach saturation content?

Apr 10, 2017

Saturation describes an equilibrium condition.........and is a function of temperature

#### Explanation:

And we can represent this is as...........

${H}_{2} O \left(l\right) r i g h t \le f t h a r p \infty n s {H}_{2} O \left(g\right)$

This always occurs, and must be accounted for when we collect a gas by bubbling the gas into an inverted container filled with water, which the gas displaces. When the level of water in the container is equilibrated with that of the OUTSIDE container:

${P}_{\text{container"=P_"the gas you are collecting}} + {P}_{S V P}$

${P}_{\text{SVP"="saturated vapour pressure}}$, is a function of temperature, for details see here. ${P}_{\text{SVP}}$ is often conveniently quoted in $m m \cdot H g$, so that you can subtract it off the pressure reading of your collected gas (which is commonly collected at an ambient pressure of $760 \cdot m m \cdot H g$).