Two structural isomers, n-hexane (CH3CH2CH2CH2CH2CH3) and 2,2-dimethylbutane [(CH3)3CCH2CH3], are liquids at room temperature.
Some measured properties are given:
• Boiling point of n-hexane: 69 °C
• Boiling point of 2,2-dimethylbutane: 58 °C
• Density of each liquid at 25 °C is nearly identical.
Answer the following questions about these data.
(a) Using intermolecular forces and molecular shape, account for the difference in normal boiling point between the two isomers.
(b) Predict which isomer will have the larger surface tension at 25 °C. Justify your answer in terms of molecular interactions.
(c) If equal-volume samples of the two liquids are simultaneously poured through identical narrow capillary tubes at 25 °C, which sample will reach the bottom first? Explain your reasoning based on viscosity differences.