Large intermolecular forces in a substance are manifested by __. question 5 options:
low vapor pressure
high boiling point
high heats of fusion and vaporization
high critical temperatures and pressures
all of these
The Correct Answer and Explanation is:
The correct answer is “all of these.”
Explanation:
Intermolecular forces refer to the attractive forces that exist between molecules in a substance. These forces include hydrogen bonds, dipole-dipole interactions, and London dispersion forces. The strength of these forces directly influences various physical properties of a substance, including its vapor pressure, boiling point, heat of fusion, heat of vaporization, and critical temperature and pressure. Here’s how large intermolecular forces manifest in each of the given options:
- Low Vapor Pressure: Vapor pressure is the pressure exerted by a gas when the substance is in equilibrium between its liquid and vapor phases. Substances with strong intermolecular forces hold their molecules tightly, making it harder for molecules to escape into the gas phase. This results in a low vapor pressure.
- High Boiling Point: The boiling point is the temperature at which a liquid transitions to a gas. Strong intermolecular forces require more energy to overcome, so substances with large intermolecular forces generally have high boiling points. This is why water (which has hydrogen bonds) has a much higher boiling point compared to other molecules of similar size (like methane).
- High Heats of Fusion and Vaporization: The heat of fusion is the energy required to change a substance from a solid to a liquid, while the heat of vaporization is the energy required to change it from a liquid to a gas. Substances with strong intermolecular forces require more energy to break these bonds, leading to high heats of fusion and vaporization.
- High Critical Temperatures and Pressures: The critical temperature is the temperature above which a gas cannot be liquefied, regardless of pressure, and the critical pressure is the pressure required to liquefy the gas at the critical temperature. Strong intermolecular forces result in higher critical temperatures and pressures because more energy is needed to overcome the interactions between the molecules.
In conclusion, large intermolecular forces result in low vapor pressure, high boiling points, high heats of fusion and vaporization, and high critical temperatures and pressures. Therefore, the correct answer is “all of these.”