Chem. Health Science: Ch. 7 Intermolecular Forces
Arrange the type of compound according to increasing boiling point, with the lowest boiling point on top and the highest boiling point on the bottom. Assume you are comparing compounds of similar size. (stronger forces = higher boiling point) - compounds exhibiting London dispersion forces - compounds exhibiting hydrogen bonding - compounds exhibiting dipole-dipole interactions
1) compounds exhibiting London dispersion forces 2) compounds exhibiting dipole-dipole interactions 3) compounds exhibiting hydrogen bonding
Sort the liquids by increasing vapor pressure, with the compound with the lowest vapor pressure on top and the highest vapor pressure on the bottom. (stronger forces = lower vapor pressure) - compounds that have only London dispersion forces - compounds that have dipole-dipole interactions - compounds that have hydrogen bonding
1) compounds that have hydrogen bonding 2) compounds that have dipole-dipole interactions 3) compounds that have only London dispersion forces
Sort the following compounds according to increasing viscosity, with the least viscous fluid on the top and the most viscous fluid on the bottom. (stronger forces = higher viscosity) - compounds with dipole-dipole interactions - compounds with hydrogen bonding - compounds with London dispersion forces
1) compounds with London dispersion forces 2) compounds with dipole-dipole interactions 3) compounds with hydrogen bonding
Sort the three states of matter by increasing order of particles. The most organized state of matter goes on the bottom and the most disorganized goes on top. - solid - gas - liquid
1) gas 2) liquid 3) solid
Correctly match each compound with the intermolecular forces it exhibits. Compound: - C2H6 - CH3F Intermolecular Force: - London dispersion and dipole-dipole interactions - only London dispersion forces
C2H6: only London dispersion forces CH3F: London dispersion and dipole-dipole interactions
Match each compound with the intermolecular forces it is capable of exhibiting. Compound: - C3H8 - CH3Cl - CH3OH Intermolecular Force: - London dispersion and dipole-dipole interactions - London dispersion, dipole-dipole interactions, and hydrogen bonding - only London dispersion
C3H8: only London dispersion CH3Cl: London dispersion and dipole-dipole interactions CH3OH: London dispersion, dipole-dipole interactions, and hydrogen bonding
Which of the following processes represent phase changes? Select all that apply. a) boiling b) burning c) condensing d) melting e) freezing
a) boiling c) condensing d) melting e) freezing
Which of the phase changes listed below are exothermic? Select all that apply. a) freezing b) condensation c) melting d) sublimation e) vaporization
a) freezing b) condensation
What is the strongest type of intermolecular force? a) hydrogen bonding b) London dispersion forces c) dipole-dipole interactions d) covalent bonding
a) hydrogen bonding
Condensation is an exothermic process that occurs when gas molecules return to what phase? a) liquid b) solid c) gas
a) liquid
What phase changes are indicated on a heating curve? Select all that apply. a) melting b) sublimation c) evaporation d) deposition
a) melting c) evaporation
What is specific heat? a) the amount of heat required to raise the temperature of 1 g of a substance by 1 degrees Celsius b) the amount of heat required to vaporize one gram of a given substance c) the temperature at which a substance passes from the vapor phase into the liquid phase
a) the amount of heat required to raise the temperature of 1 g of a substance by 1 degrees Celsius
Select the statement that best describes the melting point of a compound. a) the melting point is the temperature at which a solid is converted to a liquid b) the melting point is the temperature at which a solid is converted to a gas c) the melting point is always measured in kelvins
a) the melting point is the temperature at which a solid is converted to a liquid
Which of the following statements relating to specific heat are correct? Select all that apply. a) the units of specific heat are cal/g. degrees Celsius or J/g. degrees Celsius b) a substance with a low specific heat requires more heat to raise its temperature than a substance with high specific heat c) the specific heat for a substance has the same value regardless of the size of the sample d) the units of specific heat are cal/mol. degrees Celsius or J/mol. degrees Celsius
a) the units of specific heat are cal/g. degrees Celsius or J/g. degrees Celsius c) the specific heat for a substance has the same value regardless of the size of the sample
What is the term used to describe the pressure exerted by gas molecules in equilibrium with a liquid? a) vapor pressure b) gaseous pressure c) normal boiling point d) evaporation
a) vapor pressure
A solid with no regular arrangement of particles is classified as a(n) _____ solid.
amorphous
What type of intermolecular force is exhibited by all covalent compounds? a) hydrogen bonding b) London dispersion c) dipole-dipole interactions d) polar bonding
b) London dispersion
Select all the compounds that can participate in hydrogen bonding. (select all that apply) a) HCl b) NH3 c) HF d) H2O
b) NH3 c) HF d) H2O
Select all the statements that correctly describe condensation. a) condensation requires the absorption of energy b) condensation is an exothermic process c) condensation is the opposite of melting d) condensation converts a gas to a liquid
b) condensation is an exothermic process d) condensation converts a gas to a liquid
Select all the statements that correctly describe evaporation. a) when a liquid evaporates, it releases heat to the surroundings b) evaporation is an endothermic process c) evaporation is an exothermic process d) for a liquid to evaporate, it must absorb heat from the surroundings
b) evaporation is an endothermic process d) for a liquid to evaporate, it must absorb heat from the surroundings
Select all the statements that correctly describe heat of vaporization. a) water has a low heat of vaporization because it has weak intermolecular forces b) heat of vaporization is the amount of energy needed to vaporize 1 g of a substance c) the amount of energy released in condensation equals the amount of energy absorbed during vaporization d) the heat of vaporization cannot be used to calculate the heat released when a gas condenses
b) heat of vaporization is the amount of energy needed to vaporize 1 g of a substance c) the amount of energy released in condensation equals the amount of energy absorbed during vaporization
Select all the statements that correctly describe intermolecular hydrogen bonding: a) hydrogen bonding is a type of covalent bond that forms between a hydrogen and an electronegative atom b) hydrogen bonding is an intermolecular force existing between two molecules that have hydrogens bonded to an O, N, or F c) hydrogen bonding is important to many biological molecules including DNA d) hydrogen bonding occurs when a hydrogen atom is electrostatically attracted to an oxygen, nitrogen, or fluorine atom
b) hydrogen bonding is an intermolecular force existing between two molecules that have hydrogens bonded to an O, N, or F c) hydrogen bonding is important to many biological molecules including DNA d) hydrogen bonding occurs when a hydrogen atom is electrostatically attracted to an oxygen, nitrogen, or fluorine atom
Select the answer that best completes the statement: Liquids are fluids having definite volume but no definite _____. a) intermolecular forces b) shape c) mass d) density
b) shape
What is the change in temperature of a 55.3 g sample of water, if 285 calories of heat are added? a) 285 degrees Celsius b) 1.23 degrees Celsius c) 5.15 degrees Celsius d) 21.6 degrees Celsius
c) 5.15 degrees Celsius
What phase changes are indicated on a cooling curve? Select all that apply. a) deposition b) sublimation c) freezing d) condensation
c) freezing d) condensation
A compound with stronger intermolecular forces will have _____ surface tension. a) no b) lower c) higher
c) higher
As covalent molecules increase in size, the dispersion forces _____. a) remain the same b) decrease c) increase
c) increase
A(n) _____ solid has a regular arrangement of particles with a repeating structure.
crystalline
Which statement correctly describes vaporization? a) vaporization is the process in which a substance in the gas phase is converted to the liquid phase b) freezing is the opposite of vaporization c) vaporization is an exothermic process d) in vaporization, energy is absorbed to overcome the attractive forces of the liquid phase
d) in vaporization, energy is absorbed to overcome the attractive forces of the liquid phase
Select the statement that best defines intermolecular forces. a) intermolecular forces are covalent bonds b) intermolecular forces are attractive forces that exist between atoms in a molecule c) intermolecular forces are ionic bonds d) intermolecular forces are attractive forces that exist between molecules
d) intermolecular forces are attractive forces that exist between molecules
_____ is the conversion of a gas directly to a solid.
deposition
Dipole-dipole interactions are the attractive forces between the permanent _____ of polar molecules.
dipoles
London dispersion forces are very weak interactions due to the momentary changes in _____ density in a molecule.
electron
Melting is an _____ process, requiring an input of energy.
endothermic
Classify the phase changes as endothermic or exothermic. Phase Changes: - freezing - melting
freezing: exothermic melting: endothermic
Match the relative magnitude of the specific heat of a substance with the relative magnitude of its temperature change when absorbing a fixed amount of energy. Magnitude of Specific Heat: - greater specific heat - smaller specific heat Magnitude of Temperature: - smaller temperature change - greater temperature change
greater specific heat: smaller temperature change smaller specific heat: greater temperature change
A heating curve shows how the temperature of a substance changes as _____ is added.
heat
As the temperature increases, the vapor pressure of a liquid _____.
increases
Match the types of crystalline solids with the appropriate definition. Solids: - ionic solid - molecular solid - network solid - metallic solid Def.: - composed of a lattice of metal cations surrounded by an electron cloud - composed of individual molecules in a regular arrangement - composed of oppositely charged ions - composed of a large number of atoms covalently bonded together in sheets or arrays
ionic solid: composed of oppositely charged ions molecular solid: composed of individual molecules in a regular arrangement network solid: composed of a large number of atoms covalently bonded together in sheets or arrays metallic solid: composed of a lattice of metal cations surrounded by an electron cloud
Correctly match each process below with the phase change it represents. Process: - sublimation - evaporation - condensation Phase Change: - solid to gas - gas to liquid - liquid to gas
sublimation: solid to gas evaporation: liquid to gas condensation: gas to liquid
True or False: The value of the heat of fusion can be used to calculate both the amount of energy released in freezing and the amount of energy absorbed during melting.
true
_____ is a measure of a liquid's resistance to flow.
viscosity
