Organic Chem Test 2

  1. 5 bonding patterns in which resonance occurs
    • Allylic lone pairs
    • Allylic positive charge
    • Lone pair of electrons adjacent to a positive charge
    • A pi bond between two atoms with differenct electronegativities
    • Conjugated pi ponds in a ring
  2. Vinylic position
    directly bonded to a C=C double bond
  3. Allylic position
    Bonded one atom away from a C=C double bond
  4. Delocalization
    A very stabilizing force in which electrons are in resonance
  5. Bronsted-Lowry definition of acid/base reactions
    • Acids donate a proton
    • Bases accept a proton
  6. Reduction reaction
    Results in a net increase in the number of C-H bonds, or a net decrease in the number of C-O bonds or equivalent
  7. Oxidation reaction
    Results in a net decrease in number of C-H bonds or a net increase in the number of C-O bonds or equivalent
  8. What leads to a carboxylic acid?
    Addition of a molecule of water to the aldehyde followed by a second oxidation
  9. Homolytic bond cleavage
    Both atoms break equally and leave with the same number of electrons
  10. Heterolytic bond cleavage
    One atom breaks off with a larger portion of electrons creating ions of both atoms.
  11. A (-) sign for ΔG tells us...
    A process is product favored (spontaneous)
  12. A lower Energy of Activation results in...
    A greater reaction rate
  13. Where do transition states occur?
    An an energy maxima. (peaks on a graph)
  14. Where do intermediates occur?
    At an energy minima. (low points between peaks)
  15. A catalyst can provide a more favorable pathway for an organic reaction by...
    • Increasing the susceptibility of an electrophile to nucleophilic attack
    • Increasing the reactivity of a nucleophile
    • Increasing the leaving ability of a group by converting it to a weaker base
    • Increasing the stability of a transition state
  16. What is the order of operations in a Mass Spectrometer?
    • Sample introduction
    • Ionization
    • Mass Analysis
    • Ion detection/data analysis
  17. ESI
    Electrospray ionization: takes sample, mixes with a liquid, and sprays solution (which is highly charged) causing the molecules to fragment until its a 1+ charge
  18. EI
    Electron Impact: putting a molecule in front of a filliment and shooting electrons at it in an attempt to change its charge
  19. MALDI
    Matrix assisted laser disorption ionization: shoots powerful laser at sample which is partially protected by the matrix which absorbs some of the energy. This changes the charge of the molecule
  20. Ion separation (analyzer)
    Quadruple mass spectrometer design. Shoots ions through a tube and allows them to be analyzed. Ions cannot touch sides of tube.
  21. Nominal molecular mass
    the molecular mass to the nearest whole number
  22. The peak with the largest m/z value represents...
    the molecular ion (M)
  23. What are fragment ion peaks?
    Peaks with smaller m/z values, represent positively charged fragments of the molecule
  24. The more stable a fragment...
    The more that will be observed in the mass spectrum
  25. Fragmentation behavior of Alkyl, Halides, Ethers, and Alcohols
    • A bond between carbon and a more electronegative atom breaks heterolytically
    • A bond between carbon and an atom of similar electronegativity breaks homolytically
    • The bonds most likely to break are the weakest bonds and those that lead to formation of the most stable cation
  26. What kind of frequencies, wavenumbers, and wavelengths are associated with high energy?
    • High frequencies
    • Large wavenumbers
    • Short wavelengths
  27. Types of bending vibrations in IR
    • Scissor: inward towards central atom
    • Rock: two branched atoms are pulled in one direction
    • Twist: two branched atoms twist in opposite directions
    • Wag: two branched atoms twist in same direction
  28. When a bond stretches...
    The increasing distance between atoms increases the dipole moment
Card Set
Organic Chem Test 2
chem test 2