To determine the molecular formula and possible functional groups of the unknown compound, we can follow these steps:1. Determine the molecular formula based on the molecular ion peak.2. Analyze the fragmentation peaks to deduce possible functional groups.Step 1: Determine the molecular formula based on the molecular ion peakThe molecular ion peak is at m/z 158, which corresponds to the molecular weight of the compound. We can use this information to determine the molecular formula. A common approach is to use the nitrogen rule, which states that if a compound has an odd number of nitrogen atoms, its molecular ion peak will have an odd mass, and if it has an even number of nitrogen atoms, its molecular ion peak will have an even mass. Since the molecular ion peak is at m/z 158, which is an even number, the compound likely has an even number of nitrogen atoms 0, 2, 4, etc. .Next, we can use the molecular weight to estimate the number of carbon, hydrogen, and other heteroatoms such as oxygen, nitrogen, sulfur, etc. in the compound. A rough estimation can be made using the following average atomic masses:- Carbon C : 12- Hydrogen H : 1- Oxygen O : 16- Nitrogen N : 14- Sulfur S : 32For example, a compound with a molecular weight of 158 could have a molecular formula of C10H18O 10 carbons, 18 hydrogens, and 1 oxygen . This is just an example, and other combinations of atoms could also result in a molecular weight of 158.Step 2: Analyze the fragmentation peaks to deduce possible functional groupsThe fragmentation peaks are at m/z 132, 104, and 77. These peaks can provide clues about the functional groups present in the compound. We can analyze the differences between the molecular ion peak and the fragmentation peaks to deduce which functional groups may be present.- 158 - 132 = 26: This difference could correspond to the loss of a -C2H2 ethyne group, suggesting the presence of an alkyne functional group in the compound.- 158 - 104 = 54: This difference could correspond to the loss of a -C4H6 butadiene group, suggesting the presence of a diene or conjugated diene functional group in the compound.- 158 - 77 = 81: This difference could correspond to the loss of a -C6H9 hexatriene group, suggesting the presence of a triene or conjugated triene functional group in the compound.Based on this analysis, the unknown compound could have a molecular formula of C10H18O and may contain alkyne, diene, or triene functional groups. Further analysis, such as infrared spectroscopy or nuclear magnetic resonance spectroscopy, would be needed to confirm the functional groups and the exact molecular formula of the compound.