Consider two different organic compounds, each with the formula \(\mathrm{C}_{2} \mathrm{H}_{6} \mathrm{O}\) . One of these compounds is a liquid at room conditions and the other is a gas. Write Lewis structures consistent with this observation, and explain your answer. (Hint: The oxygen atom in both structures satisfies the octet rule with two bonds and two lone pairs.)

: To begin, we need to identify the possible structural formulas for the two compounds. We know that they must have the molecular formula C2H6O and the oxygen atom should have two bonds and two lone pairs, according to the octet rule: 1. Hydroxyl group: The oxygen atom forms a single bond to one carbon and a single bond to a hydrogen atom. 2. Ether group: The oxygen atom forms a single bond to each of the carbon atoms. Now we have two possible structures to work with: one with a hydroxyl group and the other with an ether group.

: Using the structural formulas, we can now draw Lewis structures for each compound: 1. Hydroxyl group compound: In this structure, the oxygen atom forms a single bond with one carbon and a single bond with a hydrogen atom, with two lone pairs of electrons on the oxygen atom. H H O H | | | | C-C-O-H C-C | | | | H H H H 2. Ether group compound: In this structure, the oxygen atom forms a single bond with each of the carbon atoms, with two lone pairs of electrons on the oxygen atom. H H H H | | | | C-C-O-C-C | | | | H H H H

: Now that we have both the Lewis structures, let's analyze them to determine which one would be a liquid and which one would be a gas at room temperature. 1. Hydroxyl group compound: This compound has an O-H bond, which leads to the formation of hydrogen bonding between the oxygen atom of one molecule and the hydrogen atom of another molecule. Hydrogen bonding is a strong intermolecular force, which allows this compound to maintain a relatively higher boiling point and be in liquid form at room temperature. 2. Ether group compound: In this compound, there is no hydrogen bonding as both the hydrogen atoms are connected to carbon atoms. The intermolecular forces present in this compound are van der Waals forces (London dispersion forces). These forces are weaker when compared to hydrogen bonding, so this compound would have a lower boiling point, making it a gas at room temperature. In conclusion, the compound with the hydroxyl group is a liquid at room temperature and the compound with the ether group is a gas at room temperature.