(a) The IR spectrum of gaseous N,O shows three strong absorption bands at2224 cm -1,1285

Chapter 16, Problem 16-15

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(a) The IR spectrum of gaseous N,O shows three strong absorption bands at2224 cm -1,1285 cm-I, and 2089 cm-I. In addition two quite weak bandsare observed at 2563 cm-Iand 2798 cm-lIt is known that N,O is a linearmolecule, but assume it is not known whether the structure is N-N---D orN-O-N. Use the IR data to decide between the two structures. Whatvibrations can be assigned to the strong absorption bands? What are possiblecauses of the weak absorptions?(b) The IR spectrum of HCN shows three strong absorption bands at 3312 cm-I,2089 cm-I, and 712 cm-1 From this information alone, can you deducewhether HeN is linear or nonlinear? Assuming that HCN is linear, assignvibrations to the threc absorption bands.(c) How many fundamental vibrational modes are expected for BF]? Which ofthese are expected to be IR active? Why? Sketch the vibrations.(d) How many fundamental vibrational modes would you predict for (I) methane,(2) benzene, (3) toluene, (4) ethylene, and (5) carbon tetrachloride?