Chem 113 1st Edition Lecture 33 Outline of Last Lecture I. The Henderson Hasselbalch equationOutline of Current Lecture II. Acid-Base TitrationsIII. Curve for a strong acid-strong base titrationsIV. Calculating pH during a strong acid-strong base titrationCurrent LectureI. Acid-Base Titrationsa. In an acid-base titration, the concentration of an acid (or a base) is determined by neutralizing the acid (or base) with a solution of base (or acid) of known concentrationsb. The equivalence point of the reaction occurs when the number of moles of OH- added equals the number of moles of H3O+ originally present, or vice versac. The end point occurs when the indicator changes colori. The indicator should be selected so that its color change occurs at a pH close to that of the equivalence pointII. Curve for a strong acid-strong base titrationsa. The pH increases gradually when excess base has been addedb. The pH rises very rapidly at the equivalence point, which occurs at pH=7.00c. The initial pH is lowIII. Calculating pH during a strong acid-strong base titrationa. Initial pHi. [H3O+]=[HA]initii. pH=-log[H3O+]b. pH before equivalence pointThese 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.i. Initial mol H3O+ =Vacid + Macidii. mol OH- added=Vbase + Mbaseiii. mol OH-remaining= (mol H3O+init)-(mol OH-added)iv. [H3O+]= (mol H3O+remaining)/(Vacid+Vbase)c. pH at the equivalence pointi. pH=7.00 for a strong scid-strong base titrationd. pH beyond the equivalence pointi. Initial mol H3O+ =Vacid + Macidii. mol OH- added=Vbase + Mbaseiii. mol OH- excess= (mol OH-init)-(mol H3O+added)iv. [OH-]= (mol OH-excess)/(Vacid+Vbase)v. pOH=-log[OH-] and
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