Section 12.1 – The Condensed Phases
At a given temperature, the
_________________________
magnitude determines whether a
substance is a solid, liquid, or gas. & intermolecular forces
What is essentially negligible in gases? This is one of the
assumptions of kinetic molecular theory of gases!
What are the condensed phases? -IMF's are large enough to keep the
particles in contact w/eachother
.
In your own words, summarize the differences between
liquids and solids based on the strengths of their
intermolecular (attractive) forces. to allow flow
-
In liquids -
IMl is strong enough to keep particles together but weak enough
,
-
In solids-IMF's are strong enough to keep particles in fixed positions relative to one another
What properties of liquids are dictated by the magnitudes
of intermolecular forces?
surface tension viscosity vapor pressure boiling point
, ,
,
What properties of solids are dictated by the magnitudes
of intermolecular forces?
vapor pressure and melting point
Section 12.2 – Properties of Liquids
Surface Tension
Define surface tension: the amount of energy required to stretch or
increase the surface of a liquid by unit area
A liquid with strong intermolecular forces has a
__________
high surface tension. ↑ surface tension ↑ IMF =
Consider samples of water and hexane (C H ). Which 6 14
liquid has a higher surface tension? Explain your answer
in terms of intermolecular forces. water be it's highest IMF
is Hydrogen bonds but Cotty highest force is dispersion .
,
, Attraction blw like molecules Attraction b/w unlike molecules
& ↑
What is the difference between cohesion and adhesion? =>
Viscosity attraction isverse
Define viscosity:
The higher the viscosity, the ____________
slower a liquid flows.
How is a liquid’s viscosity impacted by temperature?
↑ temperature ↓ viscosity inverse relationship
=
How is a liquid’s viscosity impacted by the strength of
intermolecular forces? liquids w/strong IMF's have higher viscosities
↑ IMF =
↑ viscosity direct relationship
Vapor Pressure of Liquids
The molecules in a liquid are in constant __________,
motion and
they have a distribution of ___________________.
Kinetic energies If a
molecule at the surface of a liquid has sufficient
______________,
Kinetic energy it can escape from the liquid phase into
the gas phase. This phenomenon is known as
_______________
evaporation or _________________.
vaporization
Molecules in the gas phase can return to the liquid phase
if they strike the liquid surface and again become trapped
by intermolecular forces, a process known as
condensation
_____________________.
What is a dynamic equilibrium? A situation where a forward process
and reverse
process are occurring at the same rate
Define equilibrium vapor pressure: The pressure exerted by the
molecules that have escaped to the gas phase ,
once the pressure has stopped
increasing.
How is the average kinetic energy of molecules in a liquid
impacted by temperature?
TAKE =
T Temp
How is the vapor pressure of a liquid impacted by
that imais
temperature? Hemp onlyfactor
↑ vapor pressure =
↑ Temp isthe
The Clausius-Clapeyron equation relates the vapor
pressure of a liquid to the temperature. Write this equation