CHEM 122 1st Edition Lecture 24Outline of Last LectureI. Chemical reactions becoming more efficientII. Shifts in Equilibriuma. Le Chatelier’s PrincipleOutline of Current Lecture I. Acids and Basesa. Arrhenius’s definitionb. Bronsted’s definitionc. CharacteristicsII. Conjugate Acid-Base PairsIII. Chemical structure of acidsa. Binary Hydridesb. Oxoacidsc. Carboxylic AcidsCurrent LectureAcids and Bases- Arrhenius’s Definitiono Acid: a substance that increases the hydrogen ion concentration in watero Base: a substance that increases the hydroxide ion concentration in water- Bronsted’s DefinitionThese 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 Acid: a substance that transfers a hydrogen ion to another substance. (proton donor)o Base: a substance that accepts a hydrogen ion from another substance (proton acceptor). - Characteristics of Acids:o Hoave a sour tasteo Turns litmus paper redo React with many metals to realease diatomic hydrogen- Characteristics of Bases:o Have a bitter tasteo Have a slippery feelo Turns litmus paper blue- Short hand Notation: when water is in the equation it creates an hydronium ion. When water is added to the equation but isn’t a reactant it creates an hydrogen ion.- Amphoteric substance: a substance that can act as either an acid or a base. Water can be this.Conjugate Acid-Base Pairs: corresponding acid base pairs that only differ by one hydrogen ion.- The position of an acid base equilibrium favors the weaker acid and base.- Relationship between relative strengths of conjugate acid base pairs:o Their strengths are inversely related Stonger the conjugate acid, weaker the conjugate baseo Strong acid completely dissociates, going into completion. A weak acid only partially dissociates and then creates an equilibrium.o Seven strong acids to know: HNO3: nitric acid HClO4: perchloric acid HClO3: chloric acid H2SO4: sulfuric acid HCl: hydrochloric acid HBr: Hydrobromic acid HI: Hydroiodic acidChemical structures of Acids:- Binary Hydrides: contain hydrogen and one more elementoHaXo as you go left of the periodic table and down the acid strength increases.- Oxoacids: very common; contains one or more OH group bound to the central atom.o Ex) HClO4- 1 OH group H2SO4- 2 OH groups HNO3- 1 OH groupo Trends in acidity: For homologous series (same central atom) the acidity increases with increasing number of oxygen atoms bound to the central atom. For oxoacids that have the same number of oxygen atoms, acid strength increases with increasing electronegativity.- Carboxylic Acidso The conjugate base of a carboxylic acid is called a carboxylate
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