Because water vapor, uncontained, will diffuse out into the atmosphere and is not close enough to condense back into the liquid water, so no equilib. can be established.
N=N₀*2^(-t/T)
N₀=200 g
T=10 d
t=30 d
N=200*2^(-30/10)=25 g
25 g will remain
Just multiply 151 x 0.0001
That will equal:
0.00151 km or if you want to round it then it would be 0.02km
