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NMR stands for Nuclear Magnetic Resonance Spectroscopy. This is the technique used for determining the structure of organic compounds.

The number of signals present in NMR reflects the number of magnetically different protons. Thus the number of signal reflects the number of chemically different protons or sets of protons. For example, methanol has two different sets of protons (methyl and hydroxyl).

Degree of unsaturation is also known as double bond equivalent (DBE). If the molecular formula is given, plug in the number into this formula.

$\mathrm{DBE}=\frac{2\mathrm{C}+2+\mathrm{N}−\mathrm{X}−\mathrm{H}}{2}$

Where, C is the number of Carbon.

N is the number of nitrogen.

H is the number of hydrogen.

X is the number of halogen.

For ${\mathrm{C}}_6{\mathrm{H}}_{14}$,

$\begin{array}{l}\mathrm{DBE}=\frac{2\left(6\right)+2+0−0−14}{2}\\ \underset{}{}\underset{}{}\underset{}{}\underset{}{}=\frac{0}{2}\\ \underset{}{}\underset{}{}\underset{}{}\underset{}{}=0\end{array}$

The actual formula ${\mathrm{C}}_6{\mathrm{H}}_{14}$, corresponds to zero degree of unsaturation, which means there is absence of double bond and ring in the compound.

2,3-dimethylbutane is the compound responsible for ¹H NMR spectrum.

The ¹H NMR spectrum of 2,3-dimethylbutane shows two signals.

No. of peaks: a = doublet, b = septet.