For the molecule ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{OH}$ (ethanol), how many distinct $1^H$ NMR signals are expected?

• A. $3$
• B. $1$
• C. $2$
• D. $4$

Answer: (A)

Verified step by step guidance

1. Identify the different types of hydrogen environments in ethanol (CH\_3CH\_2OH). Each unique environment corresponds to a distinct \( ^1H \) NMR signal.
2. Look at the \( CH_3 \) group: the three hydrogens are equivalent because they are attached to the same carbon and have the same surroundings, so they produce one signal.
3. Examine the \( CH_2 \) group: the two hydrogens are equivalent to each other but different from the \( CH_3 \) hydrogens and the hydroxyl hydrogen, so they produce a second signal.
4. Consider the hydroxyl (\( OH \)) hydrogen: it is in a unique environment and typically appears as a separate signal, giving a third distinct signal.
5. Conclude that ethanol has three distinct types of hydrogens, so it will show three distinct \( ^1H \) NMR signals.