100 。 70 860 540 I CH3(CH2CH3 (C-H bending) 30 -CH (C-H bending 10 (C-H stretching) (C-H stretching) 40003600320028002400200018001600140012001000800650 Wavenumber(cm-1) Figure 2.11 The IR spectrum of octane (Notice that, in IR spectra, the peaks are usually measured in transmittance Thus, the peak at 2900 cm"has 10% transmittance, that is, an absorbance, A, of 0.90) Copyright 2000 John wiley and Sons, Inc