Answer Happy

The molecules propene (C3H6) and vinyl chloride (C2H3CI) are shown below. H CH3 . H CI / C=C C=C co H H H Н. Propene Vinyl Chloride Comparing the C=C stretching vibrations in the two molecules, one is found in the IR spectrum at 1680 cm-1 and the other at 1645 cm-1. Which C=C double bond absorbs at which frequency and why? O A. Propene absorbs at the higher frequency (1680 cm-1). The C=C bond in vinyl chloride is weaker than the C=C bond in propene because of electron donation from the chlorine atom. Stronger bonds vibrate at a higher frequency. B. Vinyl chloride absorbs at the higher frequency (1680 cm-1). The C=C bond in vinyl chloride is stronger than the C=C bond in propene because of electron donation from the chlorine atom. Stronger bonds vibrate at a higher frequency. C. Propene absorbs at the higher frequency (1680 cm 1). The C=C bond in vinyl chloride is weaker than the C=C bond in propene because of the increased electronegativity of the chlorine atom. Stronger bonds vibrate at a higher frequency. O D. Vinyl chloride absorbs at the higher frequency (1680 cm-1). The C=C bond in vinyl chloride is stronger than the C=C bond in propene because of the increased electronegativity of the chlorine atom. Stronger bonds vibrate at a higher frequency. O E. Propene absorbs at the higher frequency (1680 cm-1). The C=C bond in vinyl chloride has a larger reduced mass than the C=C bond in propene due to the heavier chloride atom. The greater the reduced mass of the bond, the lower the vibrational frequency.