Chapter 11 Flashcards
What force holds particles together in liquids?
intermolecular attractive forces
What does increasing pressure or decreasing temerpature casue the liquid particles to do?
lock particles ina crystalline arrangement
How can you transfomr a gas to a liquid?
temerpature of a gas decreases, average kinetic energy decreasing allowing the attractions between teh paeticles to draw the particles close together,
increasing the pressure
As attractive forces get stronger what happens to the temerpature at which teh liquid boils?
increases
What happens to the melting point as intermolecular forces increase?
increases
What are the three types of intermolecualr forces?
dipersion forces, dipole-dipole attractions, hydrogen bonding
What is dispersion froce
resulting from attraction between induce dipoles
What does dipersion force depend on?
polarizability
what is polarizability?
the ease with which the electron cloud of an atom or a molecule is distorted by an outside influence, inducing a dipole moment
What does polarizability do as number of electrons increase?
increases
What does polarizability do as volume increases?
increases
What does dipersion force do as molecular weight increases?
increases
What happens to boiling point as dipersion froces increase(get stronger)
increases
Does linear molecules increase or decrease the dipersion forces?
increases
Does spherical molecules increase or decrease the dipersion force?
decreases
If a substance is hard to polarize what happens to the boling point?
decreases
What are dipole-dipole interactions?
a force that becomes significant when polar molecules come in close contact with one another
What effeces dipole-dipole interactions?
increaes polarity
When dipole moment increases what does the boiling poiint do?
increase
Which is bigger dipole-dipole interaction or disperison forces when the two molecules are the same size and shape?
dipole-dipole interactions
Which is more domiant if one molecule is larger than another? (dipole-dipole moment or dispersion forces)
dipersion force
What does boiling point do as you go down group 4A,5A,6A,and 7A elements?
increases
What is hydrogen bond?
an attraction between a hydrogen atom attached to a highly electronegative atom and a nearby small electronegative atom in another molecule or chemicla group
When electroegativity increases what does hydrogen bonding do?
increase
What does hydrogen bonding make the molecules do in ice?
makes the molecules farther apart in ice than in liquid water causing ice to be more dense
What is an ion-dipole force?
the force that exists between an ion and a polar molecule that possesses a permanet dipole moment
Which intermolecular force is found in all susbtacnaes?
dispersion forces
What kind of molecules is dipole-dipole interactions in?
All polar molecules
What kind of molecules is hydrogen bonding in?
polar molecules containing OH, NH, or HF groups
What kind of molecules is ion-dipole interactions found in?
ionic solids dissolved in polar liquids
When the molecules of two substances have the same molecular weight and shape what is the dispersion force?
equal in the two substances
When the molecule of two substance differ in molecular weight and there is no hydrogen bonding what is the disperison froces
dispersion forces tend to determine which substance has the stronger intermolecular atteactions
when they have the same shape and the same molecular weight and they have hydrogen bonding
How do you determine which one is stronger?
Which one has the most Hydrogens
What is viscosity?
the resistance of a liquid to flow
What happens to flow of a liquid when the viscoisty increases?
more slowly
What does viscosity depend on?
attractive forces between molecules as well as their shape and flexibility
As the length and flexibility of a molecule increases what happens to the viscoisty?
increases
As molecular weight increases what happens to the viscosity?
increases
What happens to the viscosity of a substance as the temerpature increases
decreases
What is surface tension?
the energy required to increase the surface area of a liquid by a amount
What are cohesive forces?
intermolecular forces taht bind similar molecules to one another
What are adhesive forces?
intermolecular forces that bind a substance to a surface
Why is there a mensicus in water?
due to the adhesive forces between the water and the glass being greater than the cohesive forces
What is capilary action?
the proces by which a liquid rises in a tube
What causes capillary action?
the combination of adhesion to the walls of the tube and cohesion between liquid particles
Does adhesive forces increase or decrease teh surface tension?
increases
When there is more carbons does it increase or decrease viscoisty?
increases
What are phase changes?
Changes of state
When a solid goes to liquid what is the name of the process?
fusion or melting
When a solid changes to a liquid does the energy increase or decrease?
energy is added(endothermic)
When a liquid changes to a solid what is it called?
freezing
When a liquid changes to a solid does it gain or lose energy?
energy is released
When a liquid changes to a gas what is it called?
vaporization
When a liquid changes to a gas does it lose or gain energy?
gain energy
When a gas goes to a liquid what is it called?
condensation
When a gas goes to a liquid does it lose or gain energy?
loses energy
When a gas goes to a solid what is it called?
Deposition
When a gas goes to a solid does it lose or gain energy?
energy is released
When a solid goes to a gas what is it called?
sublimation
When a solid goes to a gas does it lose or gain energy?
energy added
What is heat of fusion?
the enthalpy change, ∆H for melting a solid
What does vapor pressure do as temeprature increases?
increases
What is heat of vaporization?
the enthalpy change, ∆H for vaporization of a liquid
What is heat of sublimation?
the enthalpy change, ∆H for vaporization of a solid
When it is a diagnol line is it a phase change or heating up?
heating up
When it is a solid line on the heating curve is it a phase change or temperature change?
phase change
How do you find phase change?
n∆H
How do you find specific heat?
mc∆T
What is critical temperature?
the highest temperature at which a liquid phase can form
What causes critical temperature to increase?
increase in magnitude of intrmolecular forces
What is critical pressure
the pressure at which a gas at its critical temperature is converted to a liquid state
As molecular weight or polarity increases what happens to the critical temperature and pressure
increases
What is a supercritical fluid?
the state that exists when liquid and gas phases are indistinguishable from each other as the temp exceeds critical temp and the pressure exceeds critical pressure
What is vapor pressure?
the pressure exerted by a vapor in equilibrum with its liquid or solid phase
What is dynamic equilibrium?
a state of balance in which opposing process occur at the same rate
What happens to the pressure molecules that are exerted as more molecules escape?
increase
What is the boiling point of a liquid?
the temp where the vapor pressure equals the atmospheric pressure
What is the vapor pressure at for normal boiling point?
1atm or 760 torr
As boiling point increases what happens to the vapor pressure?
decreases
As boiling point increases what happens to the intermoleculr forces?
become stronger
What is pressure inversely propotional to?
temperature
What is the equation to find vapor pressure
ln(P2/P1)=-∆Hvap/R(1/T2p 1/T1)
What is a phase diagram?
a graphic way to summarize the conditions under which equlibria exist between teh different states of matter
What does C represent on the phase diagram?
critical point
critical pressure and temp
What does the red curve represent on the phase diagram?
vapor pressure cuve
What does the green curve represent on the phase diagram?
the sublimation curve
What does the blue curve represent on the phase diagram?
melting curve
What does the T represent on the phase diagram?
triple point
What is a triple point?
the temp at which solid, liquid and gas phases coexist in equilibirum
Temperature increases as you go which way on the phase diagram?
to the right
As you move up the phase digram what happens?
the pressure increases
Why is the curve of vapor pressure flipped on the H20 diagrma?
since the dneisty of solid is smaller then liquid
Why is the vapor pressure line not as curved on the carbon dioxide phase diagram?
solid is more dense then liquid
Where is sublimation located on the phase digram?
below critical pressure or critical point
