1. I am supposed to calculate the mass of water vapour in one cubic meter of air that has a relative humidity of 80% at 20°C.
2. p[v] = (eM[w]) / (RT)
Where:
p[v] = vapour density
e = water vapour pressure
M[w] = molar mass of water
R = gas constant (8,314 J / (mol*K)...