What type of feature will be observed in the EI mass spectrum of chlorobenzene?
An absorption at 3100 cm–1
No signal at all
A signal at 112 and a signal at 114 in a ratio of 3:1
A signal at 112 and a signal at 114 in a ratio of 1:1
you ever get the answer to this?
حكثمصط
To determine the type of feature observed in the EI (Electron Ionization) mass spectrum of chlorobenzene, we need to understand how EI mass spectrometry works. In EI mass spectrometry, a sample is bombarded with high-energy electrons, which causes the analyte molecules to fragment into smaller ions. These ions, along with the original molecular ion, are detected and recorded to generate a mass spectrum.
Now, let's consider the given options:
1. An absorption at 3100 cm–1:
This statement refers to infrared (IR) spectroscopy, not mass spectrometry. IR spectroscopy involves the measurement of the absorption of infrared radiation by the sample, which provides information about the functional groups present in the molecule. In mass spectrometry, we analyze the mass-to-charge ratio of ions, not absorption frequencies.
2. No signal at all:
If there is no signal observed in the EI mass spectrum, it suggests that the sample is not ionizable under the applied conditions. However, chlorobenzene is known to undergo ionization in EI mass spectrometry, so this option is unlikely.
3. A signal at 112 and a signal at 114 in a ratio of 3:1:
This option suggests the presence of two ions with mass-to-charge ratios (m/z) of 112 and 114, respectively, with a ratio of 3:1. This indicates that there are two different isotopes of the same ion, likely corresponding to different chlorine (Cl) isotopes. Because chlorobenzene contains one chlorine atom, this result is plausible.
4. A signal at 112 and a signal at 114 in a ratio of 1:1:
In contrast to option 3, this suggests that the two ions with m/z of 112 and 114 are present in equal abundances. Again, this indicates different isotopes of the same ion, which is plausible for chlorobenzene.
Based on the given options, it is either option 3 or option 4 that is more likely to be observed in the EI mass spectrum of chlorobenzene. However, without further information or data, we cannot definitively determine which one is correct.