CHEM 122 11th Edition Lecture 29 Outline of Last LectureI. Calculating polyprotic AcidsII. Properties of Solutions of Salts Outline of Current Lecture I. Buffer Solutionsa. Ideal Bufferb. Henderson-Hasselbalch EquationII. Change in pH of a Buffer SolutionIII. Acid-Base TitrationsIV. Solubility Equilibriuma. Solubility Product ConstantV. Ion ProductsCurrent LectureBuffer Solutions: resists changes in pH upon addition of strong acid or strong bases- A buffer solution consists of both an acidic and basic species is called a conjugateweak acid/base pair.- Neutralization reaction: base is neutralized by the weak base or vice versa.- A buffer consists of a relatively high concentration.o Greater the concentration the greater it resists change in pH- Ideal Buffer: equal concentrations of the conjugate acid/base pair and will also have the optimum pH value.- The pH of a buffer is determined by two factors:o Ka of the weak acidThese 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.o Relative concentrations of weak acid/base conjugate pair.- Henderson-Hasselbalch equation: pH=pKa + log([base]/[acid])Change in pH of a Buffer Solution:- Addiction of a strong acid:o This converts some of the base form of the buffer to the acid form of the buffer.o Causes the reaction to go to completion-- Addition of the strong base:o This converts some of the acid form of the buffer to the base form of the buffer.o This reaction goes to completionAcid-Base Titrations: used to determine the concentration of an acid or base solution.- Based on the stoichiometry of a neutralization reaction.- Equivalent point: moles acid= moles baseSolubility Equilibrium:- Acid-Base equilibriums: homogeneous system of the ionization for an acid or base in solution- Solubility equilibrium: ionic compounds that dissolve dissociating completely to ions, a heterogeneous system.- A solution is saturated when the rate of dissolving is equal to the rate of precipitation.- The equilibrium law for the slightly soluble salt: K= [A] [B]- Solubility-Product Constant: the equilibrium constant for the equilibrium between an ionic solid and the dissolved ions in a saturated solution.Ion Products: product of the molar concentration of dissolved ions in a solution.- For an unsaturated solution, the ion product is variable and depends on the solution- For a saturated solution, a solution with solid in equilibrium with dissolved ions, the ion product is constant (Ksp). - Solubility: mass of a substance that dissolved per liter solution (g/L)- Molar Solubility: saturation solution expressed in units of moles solute per liter
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