CH$_3$-CH$_2$-OH and CH$_3$-O-CH$_3$ The relationship between the two compounds above, is that they are

Analysis

To determine the relationship between CH$_3$-CH$_2$-OH (ethanol) and CH$_3$-O-CH$_3$ (methoxymethane/dimethyl ether), we need to compare their molecular formulas and structures.

Concept Explanation

• Isomers are compounds that have the same molecular formula but different structural arrangements of atoms.
• Allotropes are different physical forms of the same element (e.g., diamond and graphite for carbon).
• Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons.
• Isobars are atoms of different elements that have the same mass number but different atomic numbers.

Step-by-Step Solution

1. Determine the molecular formula for CH$_3$-CH$_2$-OH: • Count the atoms: 2 Carbons, 6 Hydrogens, 1 Oxygen. • Formula: C$_2$H$_6$O
2. Determine the molecular formula for CH$_3$-O-CH$_3$: • Count the atoms: 2 Carbons, 6 Hydrogens, 1 Oxygen. • Formula: C$_2$H$_6$O
3. Compare: • Both compounds have the exact same molecular formula (C$_2$H$_6$O). • However, they have different functional groups: Ethanol is an alcohol (-OH group), while dimethyl ether is an ether (-O- linkage). • Because they have the same molecular formula but different structures, they are classified as functional group isomers.

Conclusion

Since both compounds share the same molecular formula but possess different structures and chemical properties, they are isomers.

Exam Tip: Whenever you see two organic compounds with the same number of carbons, hydrogens, and oxygens, immediately check for isomerism. Remember that alcohols and ethers with the same number of carbon atoms are classic examples of functional group isomers!