Properties of Liquids

Properties of Liquids Definite volume Indefinite shape Particles close together, but can move little bit Liquids can flow

Density liquids much greater than gases Ex: DH2O(l) is 1250x greater than DH2O(g) at 25C Liquids can be compressed but change in volume very slight & requires enormous pressure

Viscosity Liquids exhibit viscosity Viscosity = resistance to flow

stronger the IMF, the higher the viscosity Viscosity depends on: strength of IMF sizes & shapes of molecules & temperature stronger the IMF, the higher the viscosity As temperature , viscosity  As temperature , viscosity 

engine oil prevents direct metal to metal contact thin film oil on surfaces prevents metal from flaking If oil too thick, won’t circulate at low temps If oil too thin, will lose film strength at high temps

Where does the marble drop fastest? Slowest? water glycerol

Viscosity & Petroleum Drilling

Surface Tension Particles at surface of liquid exist in unbalanced environment No attraction from above to balance attractions from below Surface seeks smallest possible area

Net attractive force pulling down

Surface Tension Surface Tension = E required to ↑surface area = measure of inward pull Strong intermolecular attractions  High surface tension

Surfactants Compounds that lower surface tension of H2O Disrupt hydrogen bonds between H2O molecules See video

Capillary Action Water forms concave meniscus in glass tube Attractive forces between water and glass > attractive forces between water molecules Upward movement of liquid in narrow tube = capillary action

Force(H2O-glass)  Force(H2O- H2O) Force(Hg-glass)  Force(Hg-Hg) CONVEX CONCAVE