CH 102 1st Edition Lecture 16Outline of Current Lecture I. pH Titration CurvesII. Titration of a Weak Acid with a Strong BaseIII. Titration of a Weak Base with a Strong AcidIV. Qu'est-ce que la région tamponV. Dépassement de la capacité de la mémoire tampon?VI. To Make a BufferVII. Determining the pH of a Buffer -The Henderson-Hasselbach EquationVIII. Calculating the pH of a Buffer SolutionCurrent LectureI. pH Titration Curvesa. Plot of pH as a function of titrant addedb. The titrant is eitheri. a strong base of known concentration when titrating an acidii. a strong acid of known concentration when titrating a baseII. Titration of a Weak Acid with a Strong BaseThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.a.III. Titration of a Weak Base with a Strong Acida.IV. Qu'est-ce que la région tampona. A buffer is an aqueous solution containing eitheri. A weak acid and its conjugate base, e.g. acetic acid and acetate ionii. A weak base and its conjugate acid, e. g., ammonia and ammonium ionb. A buffer resists changes in pH when small amount of acid or small amounts of base are addedc. Consider a buffer made from ammonia and ammonium ioni. Addition of a small amount of base, the base is neutralized by the ammonium ion, 1. NH4+ + OH- → NH3 + H2Oii. Addition of a small amount of acid, the acid is neutralized by the ammonia, 1. NH3 + H3O+ → + H2O + NH4+iii. The result is very little change in pH1. Except when you exceed the buffer capacityV. Dépassement de la capacité de la mémoire tampon?a. If the number of moles of acid added exceeds the number of moles of base, thenall the base is neutralized, the system is no longer a buffer and the pH is greatly decreasedb. If the number of moles of base added exceeds the number of moles of acid, thenall the acid is neutralized, the system is no longer a buffer and the pH is greatly increasedVI. To Make a Buffera. An acid bufferi. An aqueous solution of a weak acid and the salt of is conjugate baseii. e.g. acetic acid and sodium acetateb. A base bufferi. An aqueous solution of a weak base and the salt of its conjugate acidii. e.g. ammonia and ammonium chlorideVII. Determining the pH of a Buffer- The Henderson-Hasselbach Equationa. HA + H2O D H3O+ + A-i. K_a=([〖H_3 O〗^+ ][A^-])/([HA])ii. [〖H_3 O〗^+ ]=K_a ([HA])/([A^-])iii. -log [〖H_3 O〗^+ ]=-log (K_a )-log ([HA])/([A^-])iv. pH=pK_a+log ([A^-])/([HA])v. pH=pK_a+log ([base])/([acid])VIII. Calculating the pH of a Buffer Solutiona. What is the pH of a solution containing 0.100 M acetic acid and 0.200 M sodium acetatei. For acetic acid pKa = 4.74ii. [base] = [acetate] = 0.200 Miii. [acid] = [acetic acid] = 0.100 Miv. pH=pKa+log ([base])/([acid])v. pH=4.74+log 0.200/0.1001. pH =
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