Which of the following statements describe the usefulness of using 1H-NMR to distinguish between 2-(methylsulfanyl)ethyl propanoate and ethyl-3-(methylsulfanyl)propanoate?
1) 1H-NMR can differentiate between the two compounds based on their chemical shifts.
2) 1H-NMR can provide information about the number of hydrogen atoms in each compound.
3) 1H-NMR can determine the presence of any impurities or contaminants in the compounds.
4) 1H-NMR can identify the functional groups present in each compound.