Question

hexane (c₆h₁₄) has a molecular weight of approximately 86 g/mol and a boiling point of 68 degrees celsius. ethanol (ch₃ch₂oh) has a molecular weight of approximately 46 g/mol and a boiling point of 78 degrees celsius. based on this information, which options below are true? (select all that apply) ethanol has a higher boiling point because of greater london dispersion forces. both hexane and ethanol have hydrogen bonding. ethanol has a higher boiling point because of hydrogen bonding. hexane has a lower boiling point because of greater london dispersion forces. hexane must have stronger intermolecular forces based on its lower boiling point. ethanol must have stronger intermolecular forces based on its higher boiling point.

Explanation:

1. Analyze each option:

• Option 1: Ethanol has a -OH group, so hydrogen bonding (not just London dispersion) causes its higher boiling point. London dispersion forces are stronger in hexane (larger molecule), so this is false.
• Option 2: Hexane is non - polar (only London dispersion), no hydrogen bonding. Ethanol has -OH for H - bonding, so this is false.
• Option 3: Ethanol has hydrogen bonding (due to -OH), which is a strong intermolecular force. This extra force (beyond London dispersion) gives it a higher boiling point than hexane (even though hexane has stronger London dispersion due to larger size), so this is true.
• Option 4: Hexane has stronger London dispersion forces (larger molecule, more electrons) but lower boiling point because ethanol has hydrogen bonding. So saying "because of greater London dispersion forces" for lower boiling point is wrong (greater London dispersion should increase boiling point, but H - bonding in ethanol overcomes this).
• Option 5: Lower boiling point means weaker intermolecular forces. Hexane has lower boiling point, so it has weaker forces, not stronger. False.
• Option 6: Boiling point is related to intermolecular force strength (higher boiling point = stronger forces, as more energy is needed to separate molecules). Ethanol has higher boiling point, so it has stronger intermolecular forces. True.

Answer:

C. Ethanol has a higher boiling point because of hydrogen bonding.
F. Ethanol must have stronger intermolecular forces based on its higher boiling point.