Answer:
[tex]H_{2}O[/tex]
Explanation:
The definition of a Brønsted-Lowry base is that it is a substance that is capable of accepting a H+ ion using one of of its lone pairs to bond to the H+ ion. We can clearly see here that the water molecule accepts the H+ ion from NH4+ and becomes H3O+ and it is for that reason that in the forward reaction, water acts as a base.
