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Acid/Base Chemistry Part I. CHEM 2124 – General Chemistry II Alfred State College Professor Bensley. Learning Objectives. Define acid and base according to the Arrhenius concept. Define acid and base according to the Br ønsted–Lowry concept. Define the term conjugate acid-base pair.
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Acid/Base Chemistry Part I CHEM 2124 – General Chemistry II Alfred State College Professor Bensley
Learning Objectives • Define acid and base according to the Arrhenius concept. • Define acid and base according to the Brønsted–Lowry concept. • Define the term conjugate acid-base pair. • Identify acid and base species. • Define amphiprotic species. • Understand the relationship between the strength of an acid and that of its conjugate base.
Learning Objectives • Decide whether reactants or products are favored in an acid-base reaction. • Define the ion-product constant for water. • Calculate the concentrations of H3O+ and OH- in solutions of strong acids or bases. • Define pH and calculate the pH from hydronium-ion concentrations. • Calculate the hydronium-ion concentration from pH.
Introduction to Acids and Bases A. Arrhenius Definition B. The Brønsted–Lowry Definition
A− B Acid/Base Chemistry C. Proton Transfer Reactions gain of H+ H A + + H B+ conjugate acid acid base conjugate base loss of H+
Acid/Base Chemistry D. Relating Acid and Base Strength When a covalent acid dissolves in water, the proton transfer that forms H3O+ is called dissociation. A weak acid contains mostly undissociated acid, CH3COOH. A strong acid, HCl, is completely dissociated into H3O+(aq) and Cl−(aq).
Acid and Base StrengthRelating Acid and Base Strength A strong base, NaOH, is completely dissociated into Na+(aq) and −OH(aq). A weak base contains mostly undissociated base, NH3.
A− A− B B Acid/Base Chemistry E. Acid/Base Equilibrium A Brønsted–Lowry acid–base reaction represents an equilibrium. + H A + H B+ conjugate acid acid base conjugate base H A + + H B+ stronger acid stronger base weaker base weaker acid
− H O Acid/Base Chemistry F. Dissocciation of Water loss of H+ + H H O H H O H H O H + + acid base conjugate acid conjugate base gain of H+ Kw =
Acid/Base Chemistry F. Calculating pH pH = −log [H3O+]