Question

For each compound, identify the number of unique chemical signals observed by H-NMR.

1) CH4
2) C6H1(2O6)
3) C2H5OH
4) C6H6

Answer 1

For H-NMR signals: CH4 shows 1 unique signal due to equivalent hydrogens; C6H12O6 (assuming glucose) shows typically 5 signals due to the multiple hydroxyl groups; C2H5OH (ethanol) has 3 unique signals for methyl, methylene, and hydroxyl hydrogens; and C6H6 (benzene) has 1 unique signal due to its symmetrical structure.

Step-by-step explanation:

The number of unique chemical signals observed by H-NMR for each compound can be determined by considering the symmetry and the magnetic environment of the hydrogen atoms within the molecule. Here's the breakdown for the compounds listed:

1. CH4 (methane): There is only one type of hydrogen, and they are all in an identical chemical environment. Thus, methane will show 1 unique chemical signal in H-NMR.
2. C6H12O6 (assuming the compound is glucose): The exact number of signals would depend on the isomer and conformation. However, since glucose has several hydroxyl groups and is an asymmetric molecule, multiple unique signals are expected - typically 5 unique chemical signals, one for each non-equivalent hydroxyl-bearing carbon.
3. C2H5OH (ethanol): There are three types of hydrogen atoms - the methyl (CH3), the methylene (CH2), and hydroxyl (OH) hydrogens. Therefore, ethanol will typically show 3 unique chemical signals.
4. C6H6 (benzene): All of the hydrogen atoms in benzene are equivalent due to its symmetrical, hexagonal ring structure. Benzene displays 1 unique chemical signal in H-NMR.