13. For the strong acid-weak base titration of ammonia by hydrochloric acid, find the pH after 15.0 mL of 0.100 M HCl has been added to 25.0 mL of 0.100 M NH3 solution. (Kb = 1.8 x 10-5)

The reaction we will use is:

NH3 (aq) + H+ (aq) NH4+ (aq)

For the stoichiometric calculation:

NH3 (aq) H+ (aq) NH4+ (aq)
INITIAL
0.0025mol
0.0015mol
0mol
CHANGE
-0.0015mol
-0.0015mol
+0.0015mol
FINAL

What are the final numbers of moles for each species?

a) 0mol, 0mol, 0.0015mol
b) 0mol, 0mol, 0.0025mol
c) 0.0015mol, 0mol, 0.0015mol
d) 0.0010mol, 0mol, 0.0015mol