What should be the pH after 33 ml of 0.1 M NaOH was added to 40 ml of 0.05 M HCl? Chemistry Acids and Bases pH 1 Answer Doc048 Jul 3, 2017 12.25 Explanation: #33ml(0.10M NaOH) + 40ml(0.05M HCl)# => 1:1 Rxn Ratio => #0.033(0.10)"mole" NaOH + 0.040(0.05)"mole" HCl# => #0.0033 "mole" NaOH + 0.0020 "mole" HCl# =>#(0.0033 - 0.0020) "mole". "of". NaOH# in excess => #0.0013# mole #NaOH# remains in excess in 73 ml of solution. => #[NaOH]_(excess)# = #[#OH^-]# = ((0.0013"mole"OH^-)/(0.073LiterSolution))# = #0.017 M (OH^-)# => #pOH = -log[OH^-] = -log(0.017) = -(-1.75) = 1.75# => #pH = 14 - pOH = 14 - 1.75 = 12.25# Answer link Related questions How do you determine pH from pKa? How do pH values of acids and bases differ? How do you calculate something on a pH scale? How do you calculate pH diprotic acid? How do you calculate pH from acid dissociation constant? How do you calculate pH of acid and base solution? Why is the pH scale 0-14? Is pH a measure of the hydrogen ion concentration? How does solubility affect pH? How does pH relate to pKa in a titration? See all questions in pH Impact of this question 3078 views around the world You can reuse this answer Creative Commons License