CHEM 233 Final Exam Questions With Complete Solution

Mass spectrometry correct answer: Technique that sorts ions based on their mass to charge ratio Electron ionization correct answer: -Also known as hard ionization -Very energetic, produces fragments ("daughter ions") Electrospray ionization correct answer: -Also known as soft ionization -Species remains intact, form ions by attaching H+ (+1 amu) or Na+ (+23 amu) 3:1 correct answer: Mass spectrometry ratio that appears for Cl 1:1 correct answer: Mass spectrometry ratio that appears for Br Infrared spectroscopy correct answer: Technique that measures the specific wavelengths of radiation absorbed by vibrating bonds cm-1 correct answer: O-H stretch in IR; alcohols, a broad, strong band 3300 cm-1 correct answer: C-H (sp) stretch in IR cm-1 correct answer: C-H (sp2) stretch in IR cm-1 correct answer: C-H (sp3) stretch in IR 2720 cm-1 correct answer: O=C-H stretch in IR; aldehydes 2250 cm-1 correct answer: C triple bonded to C or N in IR cm-1 correct answer: C=O stretch in IR; carbonyls 1690 cm-1 correct answer: C=O stretch in IR; conjugated ketones cm-1 correct answer: C=C stretch in IR; double bonds (lower end of range) --> aromatic (higher end) <1500 cm-1 correct answer: Fingerprint region, do not analyze NMR spectroscopy correct answer: Method that determines structure using relative position of carbons and hydrogens based on the relative shielding and spins of nuclei observed in a magnetic field Number of 1H NMR signals correct answer: Number of H chemical environments Integration (1 H NMR) correct answer: Number of Hs per signal/chemical environment