True or False: Vapor pressures of a substance at 100 degrees F are always higher than the same substance at 68 degrees F

True or False: Vapor pressures of a substance at 100 degrees F are always higher than the same substance at 68 degrees F

• A. True
• B. False
• C. Not applicable
• D. Not enough data

Answer: (A)

Vapor pressure increases with temperature. As temperature rises, more molecules in a liquid gain enough energy to break free from the surface and enter the vapor phase, so the equilibrium vapor pressure rises. At 100 °F, the liquid has more energetic molecules than at 68 °F, leading to a higher vapor pressure, assuming the substance stays in the same phase and doesn’t decompose or boil away. This upward trend with temperature is observed for liquids in their liquid range and is a key factor in vapor hazard assessments, since higher vapor pressure means more vapor in the surrounding air and greater potential for ignition or inhalation exposure.

Vapor pressure increases with temperature. As temperature rises, more molecules in a liquid gain enough energy to break free from the surface and enter the vapor phase, so the equilibrium vapor pressure rises. At 100 °F, the liquid has more energetic molecules than at 68 °F, leading to a higher vapor pressure, assuming the substance stays in the same phase and doesn’t decompose or boil away. This upward trend with temperature is observed for liquids in their liquid range and is a key factor in vapor hazard assessments, since higher vapor pressure means more vapor in the surrounding air and greater potential for ignition or inhalation exposure.