ACS Organic Chemistry Best Final Exam Study Guide

ACS Organic Chemistry Best Final Exam Study Guide

9. trans: Different 10. E: Trans (in reference to alkenes) 11. Z: Cis (in reference to alkenes) 12. Ortho: 1,2 substitution 13. Meta: 1,3 substitution 14. Para: 1,4 substitution 15. Protocol for naming esters: 1) identify alkyl that is part of substituted alcohol and use this first 2) identify alkyl on other side of carbonyl and use this as a second word, ending in "-oate" (include carbonyl carbon) 16. Benzyl vs. phenyl: Benzyl: ring + CH2 Phenyl: ring 17. Aniline: Ring + NH2 18. Protocol for naming substituted amides: 1) first, name the substituted group on the nitrogen 2) then, name the group on the other side of the carbonyl, ending in "-amide" (including carbonyl carbon) 19. What is the equation for Huckel's numbers?What are Huckel's numbers?- : 4n + 2 Huckel's numbers are the number of electronsin a pisystem in aromatic compounds 20. Do lone pairs contribute to hybridization?: Yes 21. How do you draw a Lewis structure?: Determine the number of valence electrons for each atom and add them up Attempt to form octets at each atom, counting bonds as two electrons 22. How is free energy related to acidity?: In a reaction where a proton is lost, decreasing free energy implies more stability in the products, and thus more willing- ness to donate a proton, meaning more acidic. 23. What is the Gibbs free energy equation for an acid reaction?: Delta G = -RTln([A-][H3O+]/[HA][H2O]) 24. What are the factors influencing acidity?: MARIO minus M A-Atom H is bonded to R-Resonance I-Induction O-Orbitals 25. How do electron withdrawing groups influence acidity?: Electron withdraw- ing groups increase an acid's ability to donate a proton. 26. All other things being equal, is a lone pair more stable in an sp,sp2 or sp3 orbital? How does this influence acidity?: sp>sp2>sp3 because a lone pair is more stable in s orbitals than p orbitals Hs on sp hybridized atoms are more stable with the resultant lone pair, and therefore more acidic 27. Which is more stable for an acid: resonance in a ring or resonance with a carbonyl?: The carbonyl because of the electron density of O 28.In an acid, a smaller pKa means more or less acidic?: More acidic 29. Racemic mixture: Equal concentrations of enantiomers 30. Meso compound: A molecule with two or more stereocenters, but also contain- ing an internal mirror plane, meaning the compound is not overall chiral 31. Conformations vs.Configurations: Conformationsrefer to the same molecule rotated around single bonds, such as chair conformations. Configurations refer to different stereoisomers wherein conversion from one to another would require the breaking of bonds. 32.Is the boiling point of a racemic mixture the same as that of each pure enantiomer?: No 33. Strong bases tend towards what types of reactions?: SN2 or E2 34. Rank the stability of carbocations: Tertiary>Secondary>Primary>Methyl 35. Greater size = nucleophile: Stronger 36. How do allyl or benzyl groups affect the speed of an SN2 reaction?: In- crease speed 37. Do phenols undergo substitution reactions?: No 38. How does protonation affect epoxide reactions?: If the oxygen is protonated, the nucleophile will attack the more substituted carbon 39. T/F:the H atom in an elimination in a ring must be in the same plane as the leaving group.: True 40. How do polar protic solvents affect SN1, SN2, E1 and E2 reactions?: Polar protic solvents stabilize the carbocationsintermediate in SN1 and E1 reactions, and they do not hinder E2 reactions, but they will block the stereocenter/alpha carbon in SN2 reactions. 41. How does size of a molecule affect nucleophilicity in polar protic vs polar aprotic solvents?: Larger size in polar protic —> greater nucleophilicity Smaller size in polar aprotic —> greater nucleophilicity