How do you write the chemical equation and #K_b# expression for the ionization of ammonia in water? How is it safe for a window cleaner to use a solution of ammonia, which is basic?

1 Answer
Dec 15, 2016

Answer:

#NH_3(aq) + H_2O(l) rightleftharpoonsNH_4^(+) + ""^(-)OH#

Explanation:

#K_b=([H_4N^(+)][""^(-)OH])/([NH_3(aq)])# #=# #10^(-4.75)#

The concentration of #[HO^-]# in such solutions is low.

As for the use of ammonia in window cleaner, I suspect the percentage of ammonia in such a product is approx. #5-10%(w/w)#. With normal use (with gloves), the solution is probably formulated so that it is not too hard on your hands. Ammonia solutions are known to give so-called #"streak free"# finishes on glass and metal surfaces.