Answer:
0
Explanation:
If you mix NH3 and H2O the reaction is NH3 + H2O → NH4OH not NH3OH.
Te equation, like that is balanced. There is 1 N, 5H and 1 O in the reactives and 1 N, 5 H and 1 O so you have the same number of elements in the reactives and products, thus it's balanced and you don't need to do anything
This type of questions is relationed with REDOX balanced
