A chemical shift can be defined as the difference in frequency at which trimethyl silane absorbs the operating frequency of the spectrometer. Chemical shift is denoted by$\delta$. The values of chemical shift vary from 1 to 10 ppm.

The chemical shift in terms of frequency while using TMS as the reference is given as:

$\delta =\frac{{\mathrm{V}}_{\mathrm{sample}}-{\mathrm{V}}_{\mathrm{TMS}}}{{\mathrm{V}}_{\mathrm{TMS}}}\times {10}^6\mathrm{ppm}$

The value of $\delta$can change from 1 to 10 ppm.

NMR spectrum of CH₃CH₂Cl

Two kinds of protons are present in CH₃CH₂Cl , and they can split each other. The CH₃ signal will be split by CH₂ protons into 2 +1 = 3 peaks. The peak obtained will be upfield from the CH₂ protons since the CH₃ protons are farther from the Cl .

Then, the CH₂ signals will be split by the CH₃ protons into 3 + 1 = 4 peaks. The peak obtained will be downfield from the CH₃ protons since the CH₂ protons are closer to the Cl . The ratio of integration units will be 3:2.