Question

Can molecules with the molecular formulas \(\mathrm{C}_{4} \mathrm{H}_{10}\) and \(\mathrm{C}_{4} \mathrm{H}_{10} \mathrm{O}\) be structural isomers of one another? Why or why not?

Short answer

No, they cannot be structural isomers because they have different molecular formulas.

Step-by-step solution

Identify Molecular Formula

Examine the given molecular formulas \(\text{C}_4 \text{H}_{10}\) and \(\text{C}_4 \text{H}_{10} \text{O}\). Note that while both have 4 carbon atoms and 10 hydrogen atoms, one contains an additional oxygen atom.

Define Structural Isomers

Structural isomers are compounds with the same molecular formula but different structural arrangements of atoms.

Compare Molecular Formulas

Compare \(\text{C}_4 \text{H}_{10}\) (butane or isobutane) and \(\text{C}_4 \text{H}_{10} \text{O}\) (a type of butanol or methylpropanol). Notice that \(\text{C}_4 \text{H}_{10}\) has no oxygen atom, while \(\text{C}_4 \text{H}_{10} \text{O}\) does.

Determine Isomer Possibility

Since structural isomers must have identical molecular formulas, the presence of an oxygen atom in \(\text{C}_4 \text{H}_{10} \text{O}\) and its absence in \(\text{C}_4 \text{H}_{10}\) means these molecules cannot be structural isomers.

Key concepts

molecular formulas

Molecular formulas provide essential information about a molecule. They reveal the exact number of each type of atom present in the molecule. For example, the molecular formula \(\text{C}_4 \text{H}_{10}\) tells us there are four carbon atoms and ten hydrogen atoms. Similarly, the molecular formula \(\text{C}_4 \text{H}_{10} \text{O}\) indicates four carbon atoms, ten hydrogen atoms, and one oxygen atom.
This notation is crucial because it helps distinguish between different types of molecules and compounds.
By looking at these formulas, chemists can predict many chemical properties and behaviors. Molecular formulas are a basic but powerful tool for chemists to understand and classify the substances they study.

carbon atoms

Carbon atoms are the backbone of organic chemistry. They have unique properties that allow them to form long chains and complex structures. In the molecular formulas \(\text{C}_4 \text{H}_{10}\) and \(\text{C}_4 \text{H}_{10} \text{O}\), the 'C' represents carbon atoms. The number following the 'C' represents how many carbon atoms are present.
Carbon atoms can bond with each other to form various structures, including chains, branches, and rings. This versatility makes carbon essential in forming the vast array of molecules found in living organisms and synthetic materials.
In the given formulas, four carbon atoms can arrange in different ways. They can form straight chains (like in butane) or branched chains (like in isobutane). Each arrangement creates a distinct structure with unique properties.

oxygen atom

Oxygen atoms can significantly alter the properties of a molecule. In the molecular formula \(\text{C}_4 \text{H}_{10} \text{O}\), the 'O' indicates the presence of an oxygen atom.
Unlike carbon, which tends to form stable chains and rings, oxygen typically forms bonds with carbon and hydrogen in specific, reactive ways. This can create functional groups like hydroxyl groups (\text{OH}), which are common in alcohols.
In our case, the presence of an oxygen atom in \(\text{C}_4 \text{H}_{10} \text{O}\) means this molecule could be an alcohol (like butanol or methylpropanol). This oxygen atom significantly changes the molecule's chemical properties, such as its boiling point, solubility in water, and reactivity. These changes are why even a single oxygen atom can make two molecules non-isomers despite having similar carbon and hydrogen counts.