Relationship Between 1a And N-Pentane

1a) Yes, there is a correlation between the structures and the observed volatilities of compounds in Step (1a) and Step (1b). In Step (1a), n-pentane had the highest vapor pressure because the compound evaporated the fastest. N-heptane had the second highest vapor pressure, followed by n-decane with the lowest vapor pressure. The molecular structure correlates with the volatility because of the molecular weight for each compound. N-pentane is the lightest compound, followed by n-heptane and n-decane. Molecular weight relates to the strength of the intermolecular forces, therefore it would be much easier for n-pentane to evaporate compared to the other compounds. The same goes for Step (1b), in which methanol had the highest vapor pressure, followed by ethanol, and …show more content…
The intermolecular forces present in the molecules in Step (1a) include only dispersion forces, because each of the compounds are non-polar. In Step (1b), there are dispersion forces, hydrogen bonding, and dipole-dipole forces. Dispersion forces occur in all compounds, hydrogen bonding occurs between the oxygen and hydrogen atoms within each of the compounds, and there is also a dipole movement between the oxygen and hydrogen atoms. There is a correlation between IMFs and volatilities, as the stronger intermolecular forces tend to evaporate the slowest, resulting in a lower vapor pressure.

1c. The molecules included in Step (2) include n-butanol, DI water, and n-pentane. The intermolecular forces within n-butanol include dispersion forces, hydrogen bonding, and dipole-dipole forces. DI water includes the intermolecular forces of hydrogen bonding and dipole-dipole forces. N-pentane includes the intermolecular forces of dispersion forces. An additional structural feature observed is the hydrogen bonding between the compounds with oxygen and hydrogen atoms, such as water and n-butanol. The hydrogen bonds are very resilient and strong, resulting in a longer time for the compounds to