Chemistry
Chemistry
Problem
The vapor pressures of two crystalline molecular solids are listed below. Temperature (°C) | (torr) | (torr) 25 | 1.2 | 0.08 45 | 15 | 0.90 (a) Calculate the factor by which the vapor pressure of each solid increases when the temperature is raised from 25 °C to 45 °C. (b) Using the data and your calculations, identify which solid has stronger intermolecular forces and briefly justify your answer.Intuitive explanation
Vapor pressure tells you how readily molecules escape from a solid into the gas phase—a direct window into intermolecular bond strength. When temperature rises, all solids evaporate faster, but the rate of increase reveals the strength of those bonds: weak intermolecular forces mean molecules escape easily at low temperatures and pressure skyrockets with small temperature changes, while strong forces mean the solid "holds on" to its molecules and pressure rises more gradually. By comparing how much each solid's vapor pressure increases over the same temperature interval, you can rank their intermolecular forces without needing the Clausius–Clapeyron equation.
Intuitive explanation
Vapor pressure tells you how readily molecules escape from a solid into the gas phase—a direct window into intermolecular bond strength. When temperature rises, all solids evaporate faster, but the rate of increase reveals the strength of those bonds: weak intermolecular forces mean molecules escape easily at low temperatures and pressure skyrockets with small temperature changes, while strong forces mean the solid "holds on" to its molecules and pressure rises more gradually. By comparing how much each solid's vapor pressure increases over the same temperature interval, you can rank their intermolecular forces without needing the Clausius–Clapeyron equation.