Kinetic Theory Kinetic theory says particles are in constant motion, but particles of a liquid are attracted to each other. Intermolecular Attractive Forces: keep particles close together, reduce amount of space between particles. – Motion and attraction helps determine physical properties. – Why liquid has a definite volume.
Vaporization Def: conversion of a liquid into a gas or vapor. Evaporation: when this occurs on a non- boiling liquid. – Liquid evaporated faster when heated: KE of particles increases, and particles w/ highest KE escape first. As this occurs, liquid’s temperature decreases. LiquidVapor (Gas) Evaporation Condensation
Vapor Pressure Def: measure of force exerted by a gas above a liquid in a sealed container. – In constant VP, equilibrium btw liquid & vapor where evaporation of liquid = condensation of vapor. KE & VP: An increase in contained liquid temperature increases vapor pressure bc warmed particles have higher KE so they can escape the surface of the liquid and collide w/ the walls.
As temperature increases, vapor pressure increases
Pressure & Vapor Pressure Vapor pressure measured with a manometer; when liquid is added pressure increases due to VP, pushing the mercury in the manometer. – In just air, nothing happens bc pressure is same on both sides. Pressure is the force upon an object. Vapor pressure is the amount of force vapor applies to the liquid in a closed container.