Chem 211 1st Edition Lecture 20Outline of Last Lecture I. Arrhenius Acid-Base DefinitionII. Strong and Weak AcidsIII. The Acid Dissociation Constant, KaIV. Classifying the Relative Strengths of AcidsV. Classifying the Relative Strengths of BasesVI. Auto-ionization of WaterVII. The Ion-Product Constant for Water (Kw)Outline of Current Lecture I. The pH Scale,II. pH, pOH, and pKw,III. Brønsted-Lowry Acid-Base Definition,IV. Conjugate Acid-Base Pairs,V. Net Direction of Reaction.Current LectureI. The pH ScaleA. The pH of a solution indicates its relative acidity:B. The higher the pH, the lower the [H3O+] and the less acidic thesolution.II. pH, pOH, and pKwA. Kw = [H3O+][OH−] = 1.0x10−14 at 25°CB. pH + pOH = pKw for any aqueous solution at any temperature.C. Since Kw is a constant, the values of pH, pOH, [H3O+], and [OH−]are interrelated:D. If [H3O+] increases, [OH−] decreases (and vice versa).E. If pH increases, pOH decreases (and vice versa).III. Brønsted-Lowry Acid-Base DefinitionA. An acid is a proton donor, any species that donates an H+ ion.These 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.B. An acid must contain H in its formula.C. A base is a proton acceptor, any species that accepts an H+ ion.D. A base must contain a lone pair of electrons to bond to H+.E. An acid-base reaction is a proton-transfer process.IV. Conjugate Acid-Base PairsA. H2S and HS- are a conjugate acid-base pair:B. HS- is the conjugate base of the acid H2S.C. NH3 and NH4+ are a conjugate acid-base pair:D. NH4+ is the conjugate acid of the base NH3.E. A Brønsted-Lowry acid-base reaction occurs when an acid and a base react to form their conjugate base and conjugate acid, respectively.V. Net Direction of ReactionA. The net direction of an acid-base reaction depends on the relative strength of the acids and bases involved.B. A reaction will favor the formation of the weaker acid and base.C. This reaction favors the formation of the
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