Question

part c. distillation - answer the following questions concerning distillation. be sure to use complete sentences for your answers and be specific.

1. consider the following substances and their boiling points to answer the following question:

if you had a mixture of the liquids in the table above and began heating the mixture for distillation, which substance would separate out first? support your answer. (3pts)

part d. organizing data
consider the following data table:

1. how is the data table currently organized? what is the pattern that has been used? (look carefully! there is a pattern to the organization!) (2pts)

1. suppose that you are searching for a trend or pattern among these boiling points. propose a more useful way to arrange these data that might suggest how the molecules of each hydrocarbon interact. (3pts)

Explanation:

• Part C: Distillation separates substances based on their boiling points. The substance with the lowest boiling point will vaporize first and thus separate out first in the distillation process.
• Part D - 1: Looking at the hydrocarbon structures (molecular formulas), we can observe that they follow the alphabetical order of their names (e.g., Butane, Decane, Ethane, etc.).
• Part D - 2: To analyze the trend in boiling points related to molecular interactions (which are often influenced by molecular size in hydrocarbons, as larger molecules have stronger London dispersion forces), arranging the hydrocarbons in increasing order of the number of carbon atoms (which is related to molecular size) makes sense. So, we can sort them based on the number of carbon atoms in their molecular formula.

Answer:

• Part C: Acetone would separate out first. Because in distillation, substances vaporize when the temperature reaches their boiling point. Among the given substances ($2 - $Propanol: $82.4^{\circ}C$, Acetone: $56.5^{\circ}C$, Water: $100.0^{\circ}C$, Cyclohexane: $80.7^{\circ}C$), acetone has the lowest boiling point ($56.5^{\circ}C$). So, it will vaporize before the other substances when the mixture is heated for distillation.
• Part D - 1: The data table is currently organized in alphabetical order of the hydrocarbon names.
• Part D - 2: Arrange the hydrocarbons in increasing order of the number of carbon atoms in their molecular formula. For example, Methane ($CH_4$, 1 carbon atom), Ethane ($C_2H_6$, 2 carbon atoms), Propane ($C_3H_8$, 3 carbon atoms), Butane ($C_4H_{10}$, 4 carbon atoms), Pentane ($C_5H_{12}$, 5 carbon atoms), Hexane ($C_6H_{14}$, 6 carbon atoms), Heptane ($C_7H_{16}$, 7 carbon atoms), Octane ($C_8H_{18}$, 8 carbon atoms), Nonane ($C_9H_{20}$, 9 carbon atoms), Decane ($C_{10}H_{22}$, 10 carbon atoms). This arrangement would help in observing the trend that as the number of carbon atoms (molecular size) increases, the boiling point generally increases (due to stronger London dispersion forces in larger molecules).