## Chemistry: The Central Science (13th Edition)

Bronsted-Lowry acid is HCl in the forward reaction and $NH_{4}$+ in the reverse reaction. The Broasted-Lowry base is $NH_{3}$ in the forward reaction and Cl- in the reverse reaction.
HCl donates a proton (H+) to $NH_{3}$ in the forward reaction to produce $NH_{4}$+ and Cl-. Since $NH_{3}$ accepts a proton, is the Bronsted-Lowry base. The same evaluation can be applied for the reverse reaction.