Organic Chemistry 2243 Final Study Guide CHAPTER 1 Organic Chemistry Vital Force Theory The chemistry of carbon 1 Officially defined in the 19th century The Theory we might call an organic chemical came from a living organism 1 This was proven dead wrong when ammonium cyanide an inorganic compound was heated and urea an organic compound was produced Organic molecules can be made from a non natural or non living source CHAPTER 2 Bronsted Lowry Acids and Bases Acid a material that releases a proton or a hydrogen atom Base a material that donates a hydroxide ion OH Bronsted Lowry Acid donates a proton Bronsted Lowry Base accepts a proton The Citrerion for acid strength is the extent of ionization in water Strong acids ionize extensively Mineral Acid HCl HBr HI H2SO4 HNO3 and HClO are Hl strong Common Strong Bases NaOH KOH LiOH Mg OH 2 Ca OH 2 and Ba OH 2 Strong bases are extensively ionized in water Equilibrium 2 chemical reactions in competition To determine the position of the equilibrium k we must consider both reactions on either side of the arrow Typically the acid and base are on the left side of the equation and the conjugate acid and base are on the right side because the reaction is carried out to the left Weak Acids React reversibly with water to form H3O 1 They contain ionizable hydrogen atoms like nitrous acid HNO2 2 They contain cations like ammonium NH4 Solutes that react with water molecules to quire H and leave a hydroxide ion OH behind 1 Examples are ammonia and water Weak Bases Other Solvents Solvents other than water are required to put organic acids or bases into solution 1 This other solvent is usually another organic compound Diethyl ether hexane and dichloromethane are common solvents By changing the base it is possible to change the relative acidity of the acid Lewis Definitions of Acids and Bases These definitions are more general and focus on the transfer of electrons 1 Electron rich atoms donate to electron poor atoms 2 A Lewis acid will donate electron pairs to anything EXCEPT hydrogen and carbon Electrons flow from the base to the acid acids do NOT donate electrons Lewis Acid electron pair acceptor Lewis Base Electron pair donor Ate complex a reaction between a Lewis acid and base by adding on a 4th bond There is no such thing as a free proton H will not exist by itself and is always connected to something The strength of the H X bond is important The weaker the bond the stronger the acid and the easier it is to pull off More stable Less reactive Less Stable More reactive Electronegativity A property of an atom its ability to attract electrons This property increases from left to right on the periodic table and decreases going down the periodic table 1 Up and Down Size is more important than electronegativity Left to right Electronegativity is more important than size 2 More electronegative atoms will hold tightly onto their electrons and be unwilling to donate Why is HI more acidic then HF I and F are located on top of each other on the periodic table meaning that the focus should be on size rather than electronegativity Since I is a lot bigger then F the electron density of the two electrons while equal is more dispersed spread out on I Because of this the bond between the electrons and the nucleus and is weaker making I more reactive acidic The electrons on F are more localized making them easier to locate and donate a better base Strong Acid Weak Conjugate Base Weak acid Strong Conjugate Base More Electronegative Atom Will hold electrons tightly so that they may not be donated Are less reactive Are weak bases Resonance charge dispersal over multiple atoms making the atom more stable Sigma and Pi bonds Sigma bond the strongest bond because it has maximum overlap of orbitals Pi bond weaker because there is shared electron density between parallel adjacent p orbitals Why is H2SO4 is more acidic then HSO4 The charge is dispersed over a greater area on the perchlorate anion 1 The greater the charge dispersion the more stable the ion is Important Lewis Acids Boron Tetraflouride BF3 Aluminum Chloride AlCl3 Mercuric Chloride HgCl2 CHAPTER 3 Ionic Bond Displacement of electrons through chemical reactions The molecule is formed by breaking a bond to generate a positive or negative charge since it will have a counterion with an opposite charge Atoms in the outer groups will form ionic bonds Ionization Potential the energy required for the loss of one electron from one atom 2nd Ionization potential the energy required to lose 2 electrons 3rd ionization potential the energy required to lose 3 electrons Electron affinity the energy required for the gain of one electron Bond Strength Reefers to the ease of making breaking bonds in a chemical reaction Focuses on reactivity polarity Rules of Nomenclature Functional Groups collection of atoms with unique properties Substituents branches off of the parent chain called alkyl group suffix yl Suffixes are indicative of functional groups Prefixes 1 meth 2 eth 3 prop 4 but 5 pent 6 hex 7 hept 8 oct 9 nona Assign Numbers to the carbons and give substituents the lowest numbers possible More than one substituent Use Prefixes 2 di 3 tri 4 tetra 5 penta Use commas to separate numbers and dashes to separate numbers Ex 2 4 5 trimethylnonane Carbons attached in long unbranched chains Suffix ane If there are different alkyl groups like methyl and ethyl put the names in alphabetical order Alkanes Halogens No Suffix Treated like substituents Drop the ine ending and add o as the ending Cyclic Alkanes When alkanes form rings of carbon atoms General Formula CnH2n Based off the number of carbons Use the prefix cyclo to denote as a ring Substituents Rings and Chains Take the name of the ring and are treated as an alkyl substituent Give the lowest number possible or lowest combination of numbers One has to be labeled as the parent one to be labeled as a substituent 1 7 or more carbons in the chain the chain is the parent 2 6 or fewer in the chain the ring is the parent If equal in numbers can choose either one 3 The ring is attached to the chain by a substituent Alkenes Must denote the position of the double bond give it the lowest number possible takes priority General Formula CnH2n Contains 1 pi bond and 3 sigma bonds one double bond Suffix ene in naming The longest chain contains the C C unit Only 1 pi bond reacts acts as a Bronsted Lowry Acid and Base Cyclic alkane with a double bond this is always labeled 1 and 2 Formula CnH2n 2