How many NMR signals does a compound exhibit?
A compound exhibits as many signals as there are magnetic environments within the molecule.
Just because a molecule has
Let's look at 2,2-dimethyl-1-propanol.
We have 12 H atoms, but some of these have identical environments.
The 9 H atoms in the three methyl groups have the same connections. They exchange their environments constantly by rapid rotation about C-C σ bonds.
They experience the same deshielding, so they resonate at the same frequency. We say that they are chemically equivalent.
The two H atoms in the CH₂ group are also equivalent.
And the H atom in the O-H group has its own environment.
We should expect to see three signals from this compound with area ratios of 9:2:1.
Here's an actual spectrum of the compound.