CHEM-1302 _Test 1
triple point on phase diagram
3 phases exist in equilibrium
Which molecule will engage in the strongest dispersion forces? CF4 CCl4 CBr4 CI4
CI4
What forces constitute various intermolecular forces that exist between different molecules? -adhesive forces -combinatory forces -cohesive forces
adhesive forces
Dispersion forces are a type of: -intermolecular force -van der Waals force -electrostatic interaction -all of the above
all above
unsaturated solution
any solution that can dissolve more solute at a given temperature
The ________ of a liquid is the temperature at which its equilibrium vapor pressure is equal to the pressure exerted on the liquid by its gaseous surroundings. Select the correct answer below: equlibrium point boiling point freezing point melting point
boiling point
Intermolecular forces occur between particles in a substance. These particles can be: -atoms -separate molecules -both atoms and separate molecules
both atoms and separate molecules
The strength of lattice energy (bond) in salts depends on what?
charge and radius of ions
While a substance is undergoing a change in state, its temperature remains
constant
supersaturated solution
contains more than the maximum amount of solute
Which of the following is NOT weaker than a hydrogen bond? -covalent bond -dipole-dipole attraction -dispersion force
covalent bond
As temperature increases, viscosity will
decrease
In gases, usually as we increase the temperature of solvent, solubility of gas will ______-
decrease
When salt is added to water, freezing point of it __
decreases
The transition of a gas directly into the solid phase, bypassing the liquid phase, is ________. Select the correct answer below: sublimation deposition condensation melting
deposition
SO2 Intermolecular force?
dipole-dipole
breaking solute-solute attractions
endothermic
Formation of solutions where the process is endothermic or exothermic ?
exothermic
adhesive forces
forces between two different molecules
intermolecular forces
forces of attraction between molecules
Deposition
gas to solid (exothermic)
Polar molecules have attractive dipole-dipole interactions when the dipoles are arranged in which of the following geometries? Select all that apply. -head-to-tail: →→ -head-to-head: →← -side-to-side, antiparallel: ↑↓ side-to-side, parallel: ↑↑
head-to-tail and side-to-side, antiparallel
A liquid with a high resistance to flow has a _________. low melting point low viscosity high viscosity high vapor pressure
high viscosity
For solids: higher temperature results in _________ solubility
higher
The lower IMF, the _______________ vapor pressure
higher
Hydrogen bonding results in: -higher boiling points -lower boiling points -no change in boiling point
higher boiling points
When forming solution between water and molecule, water molecules surround separate molecules of solute creating _________ around each solute molecule.
hydration shell
Whst ever H bond to O,N and F is it a __________bond
hydrogen
Water exhibit high surface tension due to _____________ between molecules
hydrogen bonds
As molecule changes from one stater solid-liquid-gas, became less condensed, entropy decreases or increases? as temperature increases
increases
When salt is added to water, boiling point of it ___________
increases
Increasing the pressure of a gas
increases its solubility in a liquid
Dipole-dipole attractions increase in magnitude with: -increasing molecular mass -decreasing molecular mass -increasing bond polarity
increasing bond polarity
Dispersion forces increase with: -increasing molecular mass -decreasing molecular mass -increasing intermolecular distance
increasing mass
A gas can be liquefied by...
increasing the pressure
Dipole-dipole attractions are: -the weakest intermolecular force -the strongest intermolecular force -intermediate strength
intermediate strength
What forces are breaking in water to make solution? water breaks into molecules not atoms
intermolecular
When breaking solute - solute attraction in molecules, what forces will need to break in order to dissolve
intermolecular
When breaking solute - solute attraction in salts, what forces will need to break in order to form ions
intramolecular
How do intermolecular forces compare with intramolecular forces in terms of strength? -intramolecular forces stronger -intermolecular forces stronger -these are typically equivalent
intramolecular forces stronger
What IMF are formed in water+salt solution?
ion-dipole
Dissociation
ionic compounds separate into ions in solution
The phase of a substance depends on the relative magnitudes of the molecular _________________ and the energy of intermolecular attractions. -mass -volume -kinetic energy
kinetic energy
For gases: higher temperature results in ___________ solubility
lower
Entrapy
measure of disorder
_______ is the change of a substance from the solid state to the liquid state. Select the correct answer below: Melting Freezing Vaporization Condensation
melting
In solid, usually the higher the temperature of solvent, the ________ will dissolve
more
London dispersion forces, forces between
non-polar or neural molecules
Sugar dissolves in water because energy is given ___
off
Critical point on phase diagram
particles are moving too fast to be liquid but are too close to be gas
The type and magnitude of intermolecular forces that are present in a substance will determine that substances: -physical properties -chemical properties -both
physical
Dipole-dipole attractions occur between ______ molecules.
polar
What types of particles can participate in dipole-dipole interactions? -polar molecules -nonpolar molecules -ions
polar
Solute compounds dissolved in water can be either ____ molecular or _______ solids
polar, ionic
Most gases that are appreciably soluble in water are either ______ molecular compounds or ____ molecular compounds
polar, non-polar
Energy required to overcome the IMF is molecular solute depends on the level of
polarization
When forming solution between water and salt, water molecules surround ions in what dirrection?
positive side attaches to negative ion, while negative side to cation
colligative properties
properties that depend on the concentration of solute particles but not on their identity
Sublimation
solid to gas (endothermic)
Which phase exhibits the strongest intermolecular forces? -solids -liquids -gas
solids
The longer the hydrochain CH3, the lower is _______
solubility
Solvation
solute particles are surrounded by molecules of solvent
Hydrated
solute surrounded by water molecule
The bigger surface area , the_______ IMF will occur
stronger
Hydrogen bonding is: -the weakest intermolecular force -the strongest intermolecular force -an intermolecular force of intermediate strength
strongest
Soluability
the ability of one substance to dissolve in another
cohesive forces
the attraction between molecules in a liquid
capillary action
the attraction of the surface of a liquid to the surface of a solid
amorphous solids
the particles are not arranged in a regular pattern
Hydrogen bonding is responsible for: -the unexpectedly high boiling points for hydrides in period two -the increasing boiling points for hydrides going down a group -the low boiling points of nonpolar molecules
the unexpectedly high boiling points
Dispersion forces are: -the weakest intermolecular force -the strongest intermolecular force -an intermolecular force of intermediate strength
the weakest
The molecules are attracted equally in all directions by cohesive forces when: -they are at the surface of a liquid -they are within a liquid -they are above the liquid
they are within a liquid
Enthalpy
total energy of a system
Dispersion forces are specifically the interaction between: -two formal dipoles -an instantaneous dipole and a formal dipole -two temporary dipoles
two temporary dipoles
Intermolecular forces that occur between neutral atoms and molecules are called: -ionic bonds -covalent bonds -dispersion forces -van der Waals forces
van der Waals
types of colligative properties
vapor pressure lowering, boiling point elevation, freezing point depression, osmotic pressure
dynamic equilibrium
vaporization and condensation has equal rate
Water has all IMF forces yes/no
yes
Endothermic
Absorbs heat
Which intermolecular force is present in all condensed phases?
Dispersion forces
Condensation
Gas to liquid
What IMF are formed in water+covalent compound (molecule) solution? sugar
H bond
What holds NH3 ammonia molecules together?
H bond
Which of the following will participate in dipole-dipole interactions? C2H6 CO2 H2O
H2O
Which of the following will have the highest boiling point? CH2O CH3F H2O2
H2O2
Which species is least polarizable? Select the correct answer below: He Ne Ar Kr
He
What are cohesive forces? Select the correct answer below: Intermolecular forces between identical molecules of a substance Intermolecular forces of attraction between two different molecules Covalent bonds holding an individual molecule together Repulsive interactions that keep molecules apart
Intermolecular forces between identical molecules of a substance
Why does water have such a high surface tension? It has strong hydrogen bonding intermolecular forces holding it together. It has strong covalent bonds. It has strong adhesive forces between its molecules and a glass surface. It has strong cohesive forces between its molecules and a glass surface.
It has strong hydrogen bonding
CO2 Intermolecular force?
LDF
Dry ice CO2 IMF?
LDF
Nonpolar molecules always have ______IMF LDF dipole-dipole H-bond
LDF
Vaporization
Liquid to gas
Which of the following has dipole-dipole attractions? CO2 F2 FeCl2 PCl3
PCl3
What types of molecules will display hydrogen bonding? -All nonpolar molecules. -All polar molecules. -Nonpolar molecules containing fluorine or hydrogen. -Polar molecules containing a hydrogen directly bonded to an electronegative atom (nitrogen, oxygen, fluorine).
Polar molecules containing a hydrogen directly bonded to an electronegative atom (nitrogen, oxygen, fluorine).
Exothermic
Releases heat
What is the change from the liquid phase to the gas phase called? Select the correct answer below: Vaporization Condensation Freezing Melting
Vaporization
saturated solution
a solution that contains the maximum amount of dissolved solute
supercritical fluid
a state of matter beyond the critical point that is neither liquid nor gas
induced dipole
a temporary dipole which is created by another dipole
