OChem Theories And Practices: A Comprehensive Guide With Exercises.

Resonance rules - correct answer 1. Only electrons move. pi, lone-pair or (-) charge. Atoms DO NOT move 2. Move electrons toward the atom that doesn't have a full octet (carbonations) 3. If an atom have full octet then electrons have to come out 4. Don't move or break sigma bonds only pi bonds Greatest Resonance Contributor - correct answer 1. Have a full octet 2. smallest possible number of charges 3. (-) charge in the most electronegative atom and (+) in the least electronegative Order of stability in Newman Projections from most to least - correct answer Staggered Gauche Eclipsed staggered conformation - correct answer gauche conformation - correct answer Eclipse Conformation - correct answer _______________positions are more stable than _____________ - correct answer equatorial, axial cis - correct answer two substituents going in same direction trans - correct answer two substituents going in opposite directions Lewis acid - correct answer accepts electrons Lewis base - correct answer donates electrons the stronger the acid - correct answer the weaker its conjugate base. The stronger the base - correct answer the weaker its conjugate acid. the lower the pka - correct answer the stronger the acid the higher the ka - correct answer the stronger the acid ↑ KA = ↓ pKA = ↑ acid strength stable means - correct answer weaker the stable/ weaker the conjugate base - correct answer the stronger the acid pkas for organic compounds - correct answer CARDIO stands for - correct answer charge, atom, resonance, dipole induction, orbitals. (Charge) The more (+) charged - correct answer the more acidic (Charge) the more (-) charged - correct answer the more basic (atom) Hydrogen's acidity increases as the atom that it's bonded to: - correct answer 1. goes left-to-right across a row on the periodic table (increasing electronegativity) 2. goes down a column on the periodic table (increasing size) (Resonance) The more stable the conjugate base - correct answer the stronger the acid (Resonance) The more stable the conjugate acid - correct answer the stronger the the base (Dipole induction ) Electron Withdrawing groups - correct answer increase acidity (Dipole induction ) Electron Donating groups - correct answer decrease acidity List all the electron withdrawing groups - correct answer List all the electron donating groups - correct answer (Orbitals) From least acidic to more acidic - correct answer (less acidic) H-sp3 atom H-sp2 atom H-sp atom (more acidic) Acid and conjugate base - correct answer remove H+ If the pH of the solution is LOWER than the pka of the functional group then - correct answer the functional group will be protonated If the pH of the solution is HIGHER than the pKa of the functional group - correct answer the functional group will be deprotonated. Protonated vs deprotonated - correct answer Naming alkanes - correct answer 1. Find the longest carbon chain and count and number the carbons 2. Identify the number of substituents in the direction it gives you the lowest number. 3. Name putting the substituents in alphabetical order what is chiral carbon? - correct answer is a carbon center that contains four unique substituents. Highest priority = - correct answer highest atomic number R - correct answer clockwise S - correct answer counterclockwise Molecule that have the same chemical formula but different arrangement of the atoms - correct answer isomers diastereomers - correct answer stereoisomers that are not mirror images Enantiomers - correct answer isomers that are mirror images of each other constitutional isomers - correct answer differ in the order of attachment of atoms what are the 2 types of diastereomers? - correct answer cis/trans and E/Z E isomer - correct answer the isomer with the high-priority groups on opposite sides of the double bond Z isomers - correct answer together think: Zame (same) Enantiomers and Diastereomers - correct answer E (R,R)-- (S,S) D (R,R)--(R,S) equation for counting stereoisomers - correct answer # of possible stereoisomers = 2^n Where "n" is the # of chiral centers. Molecules that don't rotate plane-polarized light are called - correct answer achiral or inactive Chiral molecules have the ability - correct answer to rotate plane-polarized light racemic mixture is..... - correct answer 50/50 mixture of enantiomers, NOT OPTICALLY ACTIVE! Achiral meso compound - correct answer A compound with chirality centers and an internal plane of symmetry causing it to be an achiral molecule Enantiomers share extremely ____________physical properties - correct answer similar Diastereomers have very _______________physical properties, and are separated easily, such as by boiling points - correct answer different In Fischer projections; horizontal lines are used to represent vertical lines are used to represent - correct answer atoms toward us atoms away from us D sugars - correct answer the second OH group is in the right. Most carbohydrates in nature are "D" L sugars - correct answer the second OH group is in the left. Most a.a. in nature are "L" A BIG point peak at 1700+/-50 cm-1 - correct answer C=O (carbonyl) A large, broad trough far to the left - correct answer OH A LARGE, broad on top of 3000 cm-1 - correct answer COOH (carboxylic acid) Big, pointy peaks coming straight down around 3000 cm-1 - correct answer C-H's A sharp peak to the left of 3000 (around ) - correct answer 1 peak for N-H 2 peaks for NH2 amides give both amine peaks and carbonyl peaks Medium-sized peak at ~2200 - correct answer C=N (a nitrile) Vampire teeth at and - correct answer NO2