a. Calculate the hydrogen deficiency index. b. To what do the IR absorptions at 2987,1760 , and 591cm1 correspond? c. To what do the MS fragments at m/z=166/168,149/151,121/123, and 88 correspond? d. What does the intensities of the peaks at m/z=166/168,149/151, and 121/123 indicate? ropose a structure consistent with this information. Given the IR and MS spectra, identify the following unknown ith molecular formula (C6H11BrO2)