Question

How many 1H-NMR signals does each compound show?

A) One signal for each unique hydrogen environment
B) One signal regardless of hydrogen environment
C) One signal for each carbon atom
D) One signal for each molecule

Answer 1

Each compound shows one 1H-NMR signal for each unique hydrogen environment. The number of signals in an NMR spectrum corresponds to the number of different electronic environments experienced by hydrogen atoms in a molecule.

Step-by-step explanation:

The correct answer to the question "How many 1H-NMR signals does each compound show?" is A) One signal for each unique hydrogen environment. In 1H-NMR spectroscopy, each distinct set of hydrogens in a molecular structure that is in a unique electronic environment gives rise to a separate signal (a peak) in an NMR spectrum. Therefore, if a molecule has multiple hydrogen atoms, these atoms can either generate one or more signals depending on if they are in identical or different environments.

For instance, a molecule such as ethanol (CH3CH2OH) would show three distinct 1H-NMR signals corresponding to the three different environments of hydrogen atoms: the methyl group (CH3), the methylene group (CH2), and the hydroxyl group (OH).