To determine which compound exhibits the strongest overall intermolecular forces, we should consider the evaporation rate, which is indicated by the temperature change (ΔT). A larger negative ΔT means more heat is absorbed from the surroundings, and the compound with the smallest temperature change is the one that evaporates less readily. Therefore, it has the strongest intermolecular forces because stronger intermolecular forces hinder the evaporation process.
Let's examine the data:
[tex]\[
\begin{array}{|c|c|}
\hline \text { Compound } & \Delta T\left({ }^{\circ} C \right) \text{over 1 minute} \\
\hline \mathrm{C}_4 \mathrm{H}_{10} & -19.6 \\
\hline \mathrm{C}_4 \mathrm{H}_{8} \mathrm{O} & -12.1 \\
\hline \mathrm{C}_4 \mathrm{H}_{9} \mathrm{OH} & -4.3 \\
\hline
\end{array}
\][/tex]
### Analysis of the Intermolecular Forces:
1. [tex]$\mathrm{C}_4 \mathrm{H}_{10}$[/tex] (Butane):
- Has the highest temperature change (-19.6 °C).
- It evaporates the most readily.
- Hence, it has the weakest intermolecular forces among the given compounds.
2. [tex]$\mathrm{C}_4 \mathrm{H}_{8} \mathrm{O}$[/tex] (Butanal or Butanone):
- Has a moderate temperature change (-12.1 °C).
- Shows moderate evaporation.
- Intermolecular forces are stronger than butane but not the strongest.
3. [tex]$\mathrm{C}_4 \mathrm{H}_{9} \mathrm{OH}$[/tex] (Butanol):
- Has the smallest temperature change (-4.3 °C).
- Evaporates the least.
- Therefore, it has the strongest intermolecular forces among the given compounds.
From this analysis, it's clear that:
- [tex]$\mathrm{C}_4 \mathrm{H}_{9} \mathrm{OH}$[/tex] (Butanol) exhibits the strongest overall intermolecular forces because it has the smallest temperature change upon evaporation, indicating less evaporation and stronger forces holding the molecules together.
