7. An unknown, foul-smelling hydrocarbon gives the mass spectrum and infrared spectrum shown. a. Use the IR spectrum to determine the functional group(s), if any. b. Propose one or more structures for this compound. What parts of the structure are uncertain? If you knew that hydrogenation of the compounds gives n-octane, would the structure still be uncertain? c. Propose structures for major fragments at m/z37,67,81, and 95 in the mass spectrum