Question

Where does the solvent peak appear for `CDCl_3`?

Answer 1

Solvent peak appears in `H^1` spectrum as deuteration is not 100% complete and residual proton signals can be observed.

The `CDCl_3` solvent peak appears at 7.24 ppm with a multiplicity of 1 for `H^1` spectrum and 77.23 with a multiplicity of 3 for `C^13` spectrum.

Deuterium (`H^2`) has a spin quantum number (I) = 1, so n deuterium atoms will split a proton signal into `2*I*n+1` lines. This explains the multiplicity of 3 for n =1 in `C^13` spectrum.

N.B. : * This is not a correct way to represent an isotope. * The superscript should go on the left of the atomic symbol. However due to limitation of the text editor, it's presented as follows.