Which of the following pairs of chemical formulas represent isomers?

• A. C3H8 and C4H10
• B. C2H6O and C2H6O
• C. C2H6O (ethanol) and C2H6O (dimethyl ether)
• D. C4H10 and C4H10O

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the definition of isomers. Isomers are compounds that have the same molecular formula but different structural arrangements, resulting in different properties.
2. Step 2: Examine each pair of chemical formulas to see if they have the same molecular formula. For example, compare the number of carbon (C), hydrogen (H), and oxygen (O) atoms in each formula.
3. Step 3: For the pair C3H8 and C4H10, note that C3H8 has 3 carbons and 8 hydrogens, while C4H10 has 4 carbons and 10 hydrogens. Since their molecular formulas differ, they cannot be isomers.
4. Step 4: For the pair C2H6O and C2H6O, both have the same molecular formula (2 carbons, 6 hydrogens, and 1 oxygen). This means they could be isomers if their structures differ, such as ethanol and dimethyl ether.
5. Step 5: For the pair C4H10 and C4H10O, the molecular formulas differ because one contains oxygen and the other does not, so they are not isomers.