How to determine the number of HNMR signals in a compound?
The number of different HNMR signals represent the number of different hydrogens. Here are the steps you need to do to correctly identify them.
1. Label all of the hydrogens in a molecule so you don't accidentally miss one, and don'd put a signal where the hydrogen in missing. In order to label the hydrogens, we need to remember that a carbon wants to have 4 bonds. Depending on how many bonds the carbon has, is how many hydrogens we give it. For example, if it has only one bond, it will get three more hydrogens.
2. Look for lines of symmetry and show them on your molecule. A line of symmetry can be vertical, horizontal or diagonal. It cuts your molecule in half where the two halves, when folded along the line of symmetry, will completely coincide with one another. Hydrogens that are opposite of one another along the line of symmetry give the same signal.
P.S. Hydrogens on methyl groups in tert-butyl are always the same signal.
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