I will chill a container so that its outer surface is very cold, but dry. Then I will
wave the container through the air, and point out the liquid water from the air
that collects on the cold outer surface of the container.
You may suppose you have a 0.1 M solution of NH3, from:
NH4Cl + NaOH > NH3 + H2O.
Then you can compute the pH from the concentration of NH3 and its pKb.
The concentration is high enough to use the simplified formula:
[OH] = sqr(Kb*conc)
I am pretty sure the answer is 6.25 molecules
See picture for explanation
The Everglades and the Louisiana wetan are the same