Chapter 11 Flashcards
What is the fundamental difference between states of matter?
Intermolecular forces
What is average kinetic energy related too
Temperature
Condensed phases
Liquids and solids
What is a dipole?
Concentration of positive electric charge is separated from a concentration of negative charge
How do you measure the polarity of a molecule
Dipole moment (u)
How to tell if a molecule is polar ?
-contains polar bonds
-bond dipoles don’t cancel
Dispersión forces (London dispersion forces)
Temporary polarity due to unequal distribution of electrons
How to determine size of the induced dipole ?
*Polarizability of the electrons
-Volume of electron cloud
-Large molar mass
*shape of molecule
-more sour face to surface contact
Polar Molecules
Have permanent dipole
Raise boiling points and melting points relative to polar molecules of similar size and shape.
Dipole Dipole interactions
Polar molecules
Hydrogen Bonding
Hydrogen atom covalently bonded specifically to N,O, and F
Ion Dipole Interactions
Found in solutions of ions
Viscosity
Resistance of a liquid to flow , ease with molecules can move past each other, higher viscosity means higher forces
Surface tension
-Tendency of liquids to minimize their surface area
-Surface behave differently than interior
-Stronger the intermolecular forces higher surface tension
-Temperature has and inverse relationship with surface tension
Capillary action (cohesion and adhesion )
The ability of liquid to flow up a thin tube against the influence of gravity
Cohesión
Forces holding the liquid together (n)
Adhesión
Forces attracted out liquid to the tube surface
U
Meniscus
The curving of the liquid surface due to the competition adhesive and cohesive forces
Phase change
Conversions from one state of matter to another
Heat of fusion
Energy required to change solid to liquid , as melting point
Heat of vaporization
Energy required to change a liquid to gas , boiling point
Heat of sublimation
Energy required to change solid directly to gas
Tempt vs. heat
during a phase
Heating curve
-during a phase change temp does not rise
Within a phase change in temp
Q=MCAT
During a phase change at constant temp
Q=nC
Heat capacity
-heat absorbed directionally proportional to temperature , mass, and specific heat
Liquid gas Equilibrium
Liquid molecules evaporate and vapor molecules condense at the same rate
Vapor pressure
Pressure exerted by the vapor on the liquid
Factors affecting Vapor pressure
Higher T —-> higher P
Weaker forces —-> higher P
Boiling point
Liquid is at the temp at which vapor pressure = atmospheric pressure
Normal boiling point
The temp which the vapor pressure is 760 torr
The Clausius clapeyron equation
Ln(P1/P2)=(deltaHeatvap/R) [1/T2-1/T1]
Phase diagram
Is a graph showing states of matter under conditions of temperature and pressure.
Supercritical fluid
Gas and liquid have the same properties
Critical temperature
Tempt required to produce supercritical fluid
Critical pressure
The pressure at the critical temp
Triple point
All 3 phases at in equilibrium
