${ }^{13} \mathrm{C}$ NMR spectrum of DMSO- $d_{6}$ gives a signal at $\delta 39.7 \mathrm{ppm}$ as a
(a)singlet
(b)triplet
(c)quintet
(d)septet
Answer
Answer (as printed): D
Explanation
Multiplicity $= 2nI + 1$, where $n$ is the number of neighbouring protons and $I$ is the spin number of protons.For DMSO: $n = 3$, $I = 1$ (for D). Multiplicity $= 2 \times 3 \times 1 + 1 = 7$.