How to identify a compound when given the Mass spectrometry and IR spectrum?

Question

empirical for formula of C₅H₈ and is noted that one carbon is bonded to 3 other carbons but doesn't have any hydrogen bonded to it.

Answer 1

When given the mass spectrometry and IR spectrum of a compound, the following steps can be taken to help identify the compound:

1. Analyze the mass spectrometry (MS) data to determine the molecular weight and possible fragmentation patterns of the compound.
2. The molecular weight can be determined from the base peak in the mass spectrum, which corresponds to the most abundant ion in the sample.
3. The fragmentation pattern can provide information about the functional groups and connectivity of atoms in the compound.
4. Analyze the infrared (IR) spectrum to determine the presence of functional groups.
5. The IR spectrum provides information about the vibrations of functional groups in the compound, which can be used to identify the presence of certain functional groups, such as carbonyl groups (C=O) or hydroxyl groups (O-H).

In the case of the given empirical formula C5H8 with one carbon bonded to 3 other carbons, it is likely that the compound is a cyclic hydrocarbon, such as cyclopentene or cyclopentadiene. The MS data may show a molecular ion peak at m/z = 68 or 66, respectively, which corresponds to the molecular weight of C5H8. The IR spectrum may show peaks corresponding to C=C stretching vibrations and possibly a C-H bending vibration, depending on the specific compound.

Additional information, such as NMR spectroscopy or elemental analysis, may also be used to help identify the compound.