Exam 12: Structure Determination: Mass Spectrometry and Infrared Spectroscopy

The amount of energy in electromagnetic radiation is related to the frequency and wavelength of the radiation.High energy radiation like gamma rays is of:

Which of the following provides information about the functional groups present in a sample?

What m/z ratio would expect to find in the mass spectrum of the following compound due to dehydration?

Both mass spectrometry and infrared spectroscopy involve the interaction of molecules with electromagnetic energy?

Exhibit 12-6 MATCH each of the following groups of bond-types to the region of the infrared spectrum in which their absorptions occur.Place the letter of the region in the blank to the left of the bond-type. -_____ C−C,C−O,C−N,and C−X single-bond vibrations.

Consider the following spectrum. The compound used to generate this spectrum might have which of the following molecular formulas?

​When the molecular ion of 2,2-dimethylpentane fragments,the positive charge is most likely to stay on:

Exhibit 12-1 Select the most reasonable formula for the compounds with the following mass spectral data. -Refer to Exhibit 12-1.M⁺ m/z = 136 and M⁺ at m/z = 138 of approximately equal intensity

Exhibit 12-5 Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s). Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/ -Refer to Exhibit 12-5.Propose structures for fragment ions at m/z = 57,43,and 29.

The sugar glucose contains C,H,and O and has a mass of 180.0634 amu as determined by high-resolution mass spectrometry.Glucose contains an equal number of carbon and oxygen atoms.What is the molecular formula of glucose? (¹H = 1.00783 amu,¹²C = 12.00000 amu,¹⁶O = 15.99491 amu)

Cyclohexene and 2-hexyne both have the molecular formula C₆H₁₀.How would you use infrared spectroscopy to distinguish between the two compounds?

Exhibit 12-2 Use the data below to answer the following question(s). Loratidine is the active ingredient in the antihistamine Claritin .Mass spectral analysis of loratidine shows M⁺ at m/z = 382 and M⁺ at m/z = 384 in an approximate ratio of 3:1 in intensity. -Refer to Exhibit 12-2.Loratidine is known to contain nitrogen.What is the minimum number of nitrogens in loratidine?

Exhibit 12-4 The following question(s) refer to the mass spectrum shown below. Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/ -Refer to Exhibit 12-4.Calculate a possible molecular formula for this compound.

Which of the following statements best describes the base peak in a mass spectrum?

Consider the following mass spectrum Which of the following compounds might have been used to produce this spectrum?

Examining the infrared spectrum of a compound allows us to:

Exhibit 12-6 MATCH each of the following groups of bond-types to the region of the infrared spectrum in which their absorptions occur.Place the letter of the region in the blank to the left of the bond-type. -_____ N−H,C−H,and O−H stretching and bending motions.

Could you distinguish 2,2-dimethylbutane from 2-methylpentane using mass spectrometry?

​The peak in the IR absorption spectra for the alkyne group in acetylene would be observed in the range of:

Below is the mass spectrum of an unknown hydrocarbon.In addition,this hydrocarbon shows characteristic absorption at 2100 cm−¹ in its IR spectrum.Give the structure of this unknown. Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/