Ammonia gas is alkaline or acid?

Ammonia gas behaves as an alkali in water........................

Ammonia gas is exceptionally soluble in water, and an experiment called the ##"ammonia fountain"## (which you'll have to seek out on the interwebz) spectacularly demonstrates this. In aqueous solution, ammonia behaves as a weak base, and the given equilibrium lies somewhat to the right:

##NH_3(aq) + H_2O(aq) rightleftharpoons NH_4^+ + HO^-## ##;K_"eq"=10^(-4.75)##

If you are in first year university, can you tell me the ##pH## of a ##1*mol*L^-1## solution of ##NH_3(aq)##?

##K_"eq"=10^(-4.75)=([NH_4^+][HO^-])/([NH_3(aq)])##