2 Improved formatting. edit approved Apr 13 '17 at 15:26 Felipe S. S. Schneider 2,09522 gold badges1414 silver badges3333 bronze badges This is a titration problem-  -not not necessarily a buffer problem. While you have .0055$$0.0055$$ moles of NH3$$\ce{NH3}$$, you have .01$$0.01$$ moles of H$$\ce{H}$$ from HCl$$\ce{HCl}$$ dissociating. .01-.0055=.0045$$0.01 - 0.0055 = 0.0045$$ moles of H$$\ce{H}$$ left. Take H/total L to find M. Take the -log$$-\log$$ of [H]$$\ce{[H]}$$. This is a titration problem--not necessarily a buffer problem. While you have .0055 moles of NH3, you have .01 moles of H from HCl dissociating. .01-.0055=.0045 moles of H left. Take H/total L to find M. Take the -log of [H]. This is a titration problem  - not necessarily a buffer problem. While you have $$0.0055$$ moles of $$\ce{NH3}$$, you have $$0.01$$ moles of $$\ce{H}$$ from $$\ce{HCl}$$ dissociating. $$0.01 - 0.0055 = 0.0045$$ moles of $$\ce{H}$$ left. Take H/total L to find M. Take the $$-\log$$ of $$\ce{[H]}$$. 1 answered Apr 13 '17 at 13:28 Jacie 3111 bronze badge This is a titration problem--not necessarily a buffer problem. While you have .0055 moles of NH3, you have .01 moles of H from HCl dissociating. .01-.0055=.0045 moles of H left. Take H/total L to find M. Take the -log of [H].