Chapter 10: Liquids and Solids + Review of Gen Chem I Concepts Flashcards

1
Q

What is the molar mass of carbon dioxide (CO₂)?
a) 28.01 g/mol
b) 44.01 g/mol
c) 16.00 g/mol
d) 12.01 g/mol

A

b) 44.01 g/mol

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2
Q

How many moles are in 36.04 g of water (H₂O)?
a) 0.5 moles
b) 1 mole
c) 2 moles
d) 18 moles

A

c) 2 moles

  • moles are the mass divided by molar mass, so calculate molar mass of water (18 g / mol)
  • mass = 36.04 g
    — so: 36.04 / 18 = 2 moles
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3
Q

Which element has the highest electronegativity?
a) Oxygen (O)
b) Fluorine (F)
c) Nitrogen (N)
d) Hydrogen (H)

A

b) Fluorine (F)

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4
Q

Electronegativity decreases as you:
a) Move left to right across a period.
b) Move up a group.
c) Move down a group.
d) Approach the noble gases.

A

c) Move down a group

Explanation: Electronegativity decreases down a group because atoms get larger, and their outer electrons are farther from the nucleus, reducing the ability to attract shared electrons.

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5
Q

Which of the following molecules is nonpolar?
a) H₂O
b) CO₂
c) NH₃
d) HF

A

b) CO₂

Explanation:

CO₂ is a linear molecule, and the dipoles of the two C=O bonds cancel out due to symmetry, making it nonpolar.
H₂O, NH₃, and HF are all polar due to their asymmetry and/or large differences in electronegativity.

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6
Q

Why is water (H₂O) polar?
a) It contains a metal and a nonmetal.
b) The electronegativity difference between hydrogen and oxygen is very small.
c) It has a bent shape, leading to an unequal distribution of charge.
d) It is symmetrical

A

c) It has a bent shape, leading to an unequal distribution of charge.

Explanation:
The oxygen atom in H₂O is more electronegative than hydrogen, creating partial charges.
The bent geometry of the molecule prevents the dipoles from canceling out, resulting in a polar molecule.

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7
Q

What does molar mass represent?
a) The mass of a single molecule of a substance in grams.
b) The mass of one mole of particles in a substance in grams.
c) The total mass of an atom in atomic mass units (amu).
d) The number of atoms in one mole of a substance.

A

b) The mass of one mole of particles in a substance in grams.

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8
Q

How is the molar mass of a compound calculated?

a) By dividing the atomic mass by Avogadro’s number.
b) By adding the atomic masses of all atoms in the compound.
c) By multiplying the number of moles by the atomic mass.
d) By counting the number of atoms in the compound.

A

b) By adding the atomic masses of all atoms in the compound.

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9
Q

What is electronegativity?

a) The ability of an atom to lose electrons.
b) The ability of an atom in a chemical bond to attract shared electrons.
c) The amount of energy required to remove an electron from an atom.
d) The total charge of an atom after forming a bond.

A

b) The ability of an atom in a chemical bond to attract shared electrons.

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10
Q

Which statement about electronegativity is correct?

a) It decreases across a period from left to right.
b) It is the same for all elements in the same group.
c) It determines the polarity of a bond.
d) It increases as the atomic size increases.

A

c) It determines the polarity of a bond.

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11
Q

What does polarity describe in a molecule?

a) The shape of the molecule.
b) The distribution of electrical charge within the molecule.
c) The number of bonds formed by the molecule.
d) The mass of the molecule.

A

b) The distribution of electrical charge within the molecule.

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12
Q

Which of the following determines whether a molecule is polar?

a) The molecule’s molar mass and shape.
b) The number of atoms in the molecule.
c) The difference in electronegativity between atoms and the shape of the molecule.
d) The number of lone pairs on the central atom.

A

c) The difference in electronegativity between atoms and the shape of the molecule.

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13
Q

How do you calculate the mass of a substance in grams?

a) Multiply the number of moles by Avogadro’s number.
b) Divide the number of moles by the molar mass.
c) Multiply the number of moles by the molar mass.
d) Add the atomic masses of all the elements in the compound.

A

c) Multiply the number of moles by the molar mass.

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14
Q

If you have 2 moles of NaCl (molar mass = 58.44 g/mol), what is the mass in grams?

a) 29.22 g
b) 58.44 g
c) 116.88 g
d) 120.00 g

A

c) 116.88 g

Mass=2moles×58.44g/mol=116.88g

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15
Q

How many moles are in 90.12 g of H₂O (molar mass = 18.02 g/mol)?

a) 2 moles
b) 3 moles
c) 4 moles
d) 5 moles

A

c) 4 moles

90.12 g / 18.02 g = 5 moles

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16
Q

What does Avogadro’s number represent?
a) The mass of one mole of a substance.
b) The number of particles in one mole of a substance.
c) The number of molecules in one gram of a substance.
d) The molar mass of an element.

A

b) The number of particles in one mole of a substance.

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17
Q

How many molecules are in 3 moles of CO2

a. 1.80610^23
b. 6.022
10^23
c. 1.80610^24
d. 3.000
10^23

A

c. 1.806*10^24

particles = 3 moles * 6.02210^23 = 1.80610^24

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18
Q

How many moles are in 1.204*10^24 atoms of O2?

a) 1 mole
b) 2 moles
c) 3 moles
d) 4 moles

A

b) 2 moles

1.20410^24/6.02210^23 = 2 moles

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19
Q

Which of the following is true about gases?
a) They have a definite shape and volume.
b) They have a definite volume but take the shape of their container.
c) They have no definite shape or volume.
d) They are incompressible.

A

c) They have no definite shape or volume.

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20
Q

What is a characteristic property of liquids?
a) They have a fixed shape and fixed volume.
b) They have no fixed shape but a fixed volume.
c) They expand to fill the entire container.
d) They are highly compressible.

A

b) They have no fixed shape but a fixed volume.

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21
Q

Which of the following is true about solids?
a) They have no fixed shape but a fixed volume.
b) They have a fixed shape and fixed volume.
c) They take the shape of their container.
d) They are highly compressible.

A

b) They have a fixed shape and fixed volume.

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22
Q

Which of the following correctly matches the states of matter to their compressibility?
a) Gases > Liquids > Solids
b) Solids > Liquids > Gases
c) Liquids > Gases > Solids
d) Gases > Solids > Liquids

A

a) Gases > Liquids > Solids

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23
Q

What is the difference between intermolecular and intramolecular forces?

a) Intermolecular forces occur within a molecule, while intramolecular forces occur between molecules.

b) Intramolecular forces occur within a molecule, while intermolecular forces occur between molecules.

c) Intermolecular forces only occur in solids, while intramolecular forces only occur in gases.

d) There is no difference between the two; they are the same.

A

b) Intramolecular forces occur within a molecule, while intermolecular forces occur between molecules.

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24
Q

Which of the following is an example of an intermolecular force?
a) Covalent bond
b) Ionic bond
c) Hydrogen bond
d) Metallic bond

A

c) Hydrogen bond

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25
Q

Which of the following is an example of an intramolecular force?
a) Dipole-dipole interactions
b) London dispersion forces
c) Covalent bond
d) Van der Waals forces

A

c) Covalent bond

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26
Q

Why are intermolecular forces generally weaker than intramolecular forces?

a) They occur within the molecule, making them stronger.

b) They involve the sharing of electrons, which is less stable.

c) They are based on weaker attractions, such as dipole interactions or dispersion forces, rather than direct bonding.

d) They occur only in certain states of matter, making them less significant.

A

c) They are based on weaker attractions, such as dipole interactions or dispersion forces, rather than direct bonding.

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27
Q

What are dispersion forces?

a) Permanent dipole-dipole interactions between polar molecules.

b) Weak intermolecular forces caused by temporary dipoles in molecules or atoms.

c) Strong intramolecular forces that hold atoms together in a molecule.

d) Hydrogen bonding between
molecules containing hydrogen and highly electronegative atoms.

A

b) Weak intermolecular forces caused by temporary dipoles in molecules or atoms.

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28
Q

What causes dispersion forces?

a) Permanent dipoles in polar molecules.
b) Instantaneous dipoles inducing dipoles in nearby atoms or molecules.
c) The sharing of electrons between atoms.
d) The attraction between ions and polar molecules.

A

b) Instantaneous dipoles inducing dipoles in nearby atoms or molecules.

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29
Q

Which type of molecule or atom will have stronger dispersion forces?

a) Smaller molecules with lower molar mass.
b) Larger molecules with greater molar mass.
c) Nonpolar molecules only.
d) Molecules with permanent dipoles.

A

b) Larger molecules with greater molar mass.

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30
Q

Which of the following increases dispersion forces?

a) Decreasing the molecular weight of a molecule.
b) Decreasing the surface area of a molecule.
c) Increasing the molecular weight and surface area of a molecule.
d) Having a molecule with hydrogen bonds.

A

c) Increasing the molecular weight and surface area of a molecule.

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31
Q

What is an instantaneous dipole?

a) A temporary uneven distribution of electrons in a molecule or atom.
b) A permanent dipole that occurs in polar molecules.
c) A dipole that results from hydrogen bonding.
d) An ionic charge in a molecule.

A

a) A temporary uneven distribution of electrons in a molecule or atom.

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32
Q

What is an induced dipole?

a) A permanent dipole in a polar molecule.
b) A temporary dipole created when an instantaneous dipole causes electron displacement in a nearby atom or molecule.
c) A dipole caused by the sharing of electrons in a covalent bond.
d) A type of intramolecular force.

A

b) A temporary dipole created when an instantaneous dipole causes electron displacement in a nearby atom or molecule.

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33
Q

How do instantaneous and induced dipoles contribute to dispersion forces?

a) Instantaneous dipoles repel molecules, weakening dispersion forces.

b) Instantaneous dipoles create temporary attractions with nearby molecules, and induced dipoles enhance these attractions.

c) Induced dipoles form hydrogen bonds, which are a type of dispersion force.

d) Dispersion forces arise only from induced dipoles, not instantaneous dipoles.

A

b) Instantaneous dipoles create temporary attractions with nearby molecules, and induced dipoles enhance these attractions.

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34
Q

How does molecular size affect boiling points?

a) Larger molecules with more electrons have stronger dispersion forces and higher boiling points.

b) Smaller molecules with fewer electrons have stronger dispersion forces and higher boiling points.

c) Molecular size has no effect on boiling points.

d) Larger molecules have weaker dispersion forces and lower boiling points.

A

a) Larger molecules with more electrons have stronger dispersion forces and higher boiling points.

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35
Q

How does surface area influence dispersion forces and boiling points?

a) Molecules with smaller surface areas have stronger dispersion forces and higher boiling points.

b) Molecules with larger surface areas have stronger dispersion forces and higher boiling points.

c) Surface area only affects polar molecules, not nonpolar ones.

d) Surface area has no effect on boiling points.

A

b) Molecules with larger surface areas have stronger dispersion forces and higher boiling points.

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36
Q

Which of the following substances will likely have the highest boiling point?

a) CH₄ (Methane)
b) C₂H₆ (Ethane)
c) C₄H₁₀ (Butane)
d) C₆H₁₄ (Hexane)

A

d) C₆H₁₄ (Hexane)

37
Q

What are dipole-dipole attractions?

a) Weak intermolecular forces caused by temporary dipoles.
b) Strong intramolecular forces that hold atoms together in a molecule.
c) Intermolecular forces between permanent dipoles in polar molecules.
d) The attraction between ions and nonpolar molecules.

A

c) Intermolecular forces between permanent dipoles in polar molecules.

38
Q

Dipole-dipole attractions occur in which type of molecules?

a) Nonpolar molecules only.
b) Polar molecules with permanent dipoles.
c) Nonpolar molecules with temporary dipoles.
d) Ionic compounds dissolved in water.

A

b) Polar molecules with permanent dipoles.

39
Q

Are dipole-dipole attractions temporary or permanent?

a) Temporary, caused by instantaneous dipoles.
b) Permanent, caused by the alignment of polar molecules.
c) Temporary, caused by induced dipoles in nonpolar molecules.
d) Permanent, caused by ionic bonding.

A

b) Permanent, caused by the alignment of polar molecules.

40
Q

How do dipole-dipole attractions compare in strength to dispersion forces?

a) Dipole-dipole attractions are generally weaker than dispersion forces.
b) Dipole-dipole attractions are generally stronger than dispersion forces.
c) Dipole-dipole attractions and dispersion forces are the same strength.
d) Dipole-dipole attractions only occur in nonpolar molecules, so they can’t be compared.

A

b) Dipole-dipole attractions are generally stronger than dispersion forces.

41
Q

Which of the following has the strongest intermolecular forces?

a) A polar molecule with dipole-dipole interactions.
b) A nonpolar molecule with only dispersion forces.
c) A polar molecule with hydrogen bonding.
d) A molecule with induced dipoles only.

A

c) A polar molecule with hydrogen bonding.

41
Q

Which of the following is required for dipole-dipole attractions?

a) The molecule must be nonpolar.
b) The molecule must contain hydrogen atoms bonded to oxygen, nitrogen, or fluorine.
c) The molecule must be polar with a permanent dipole.
d) The molecule must have a high molar mass.

A

c) The molecule must be polar with a permanent dipole.

42
Q

Which type of molecule will exhibit dipole-dipole attractions?

a) Nonpolar molecules like CH₄.
b) Polar molecules like HCl.
c) Noble gases like Argon.
d) Ionic compounds like NaCl.

A

b) Polar molecules like HCl.

43
Q

Which of the following correctly describes dipole-dipole attractions?

a) They arise from interactions between temporary dipoles in nonpolar molecules.
b) They are stronger in molecules with greater molecular mass, regardless of polarity.
c) They occur between the positive end of one polar molecule and the negative end of another polar molecule.
d) They are the weakest type of intermolecular force.

A

c) They occur between the positive end of one polar molecule and the negative end of another polar molecule.

44
Q

What is hydrogen bonding?

a) A bond between hydrogen atoms in the same molecule.
b) A strong intermolecular force involving hydrogen and a highly electronegative atom.
c) A weak force caused by temporary dipoles.
d) A type of covalent bond within molecules.

A

b) A strong intermolecular force involving hydrogen and a highly electronegative atom.

45
Q

Which elements must be present for hydrogen bonding to occur?

a) Nitrogen (N), Oxygen (O), and Fluorine (F).
b) Hydrogen (H) and any other nonmetal.
c) Hydrogen (H) and any halogen.
d) Carbon (C), Hydrogen (H), and Oxygen (O).

A

a) Nitrogen (N), Oxygen (O), and Fluorine (F).

46
Q

Why does hydrogen bonding occur with N, O, or F?

a) These atoms are small and highly electronegative, creating a strong partial charge.
b) They are the only elements capable of forming polar bonds.
c) They have high atomic masses, making them more polarizable.
d) They are always found in ionic compounds.

A

a) These atoms are small and highly electronegative, creating a strong partial charge.

47
Q

How does hydrogen bonding affect boiling points?

a) It lowers boiling points by weakening intermolecular forces.
b) It raises boiling points by strengthening intermolecular forces.
c) It has no effect on boiling points.
d) It decreases boiling points in polar molecules but increases them in nonpolar molecules.

A

b) It raises boiling points by strengthening intermolecular forces.

48
Q

Which of the following has the highest boiling point due to hydrogen bonding?

a) CH₄ (Methane)
b) NH₃ (Ammonia)
c) H₂ (Hydrogen gas)
d) CO₂ (Carbon dioxide)

A

b) NH₃ (Ammonia)

Explanation: NH₃ exhibits hydrogen bonding because nitrogen is highly electronegative and directly bonded to hydrogen.

49
Q

Why does water (H₂O) have an unusually high boiling point?

a) It has strong ionic bonds within its molecules.
b) It has multiple hydrogen bonds between molecules.
c) It is a nonpolar molecule with strong dispersion forces.
d) It contains heavy atoms, which increase boiling point.

A

b) It has multiple hydrogen bonds between molecules.

50
Q

Rank the types of intermolecular forces from weakest to strongest.

a) Dispersion forces < Dipole-dipole attractions < Hydrogen bonding.
b) Dipole-dipole attractions < Dispersion forces < Hydrogen bonding.
c) Hydrogen bonding < Dispersion forces < Dipole-dipole attractions.
d) Dispersion forces < Hydrogen bonding < Dipole-dipole attractions.

A

a) Dispersion forces < Dipole-dipole attractions < Hydrogen bonding.

51
Q

Which statement about intermolecular forces is correct?

a) Hydrogen bonding only occurs in nonpolar molecules.
b) Dispersion forces are the only intermolecular forces present in nonpolar molecules.
c) Dipole-dipole attractions are stronger than hydrogen bonding.
d) Dispersion forces are stronger than dipole-dipole attractions.

A

b) Dispersion forces are the only intermolecular forces present in nonpolar molecules.

52
Q

Do dispersion forces occur in polar molecules?

a) No, dispersion forces only occur in nonpolar molecules.
b) Yes, but they are weaker than dipole-dipole attractions and hydrogen bonding in polar molecules.
c) Yes, and they are the dominant intermolecular force in polar molecules.
d) No, polar molecules only exhibit dipole-dipole interactions.

A

b) Yes, but they are weaker than dipole-dipole attractions and hydrogen bonding in polar molecules.

53
Q

What are cohesive forces?

a) Forces between molecules of the same type.
b) Forces between molecules of different types.
c) Forces that break surface tension.
d) Forces that increase boiling points in nonpolar substances.

A

a) Forces between molecules of the same type.

54
Q

How do cohesive forces relate to viscosity?

a) Higher cohesive forces lead to lower viscosity.
b) Higher cohesive forces lead to higher viscosity.
c) Viscosity is not affected by cohesive forces.
d) Viscosity only depends on the size of the molecule.

A

b) Higher cohesive forces lead to higher viscosity.

55
Q

What does higher surface tension indicate about a liquid’s droplets?

a) They form more irregular shapes.
b) They form larger, flat drops.
c) They form more spherical droplets.
d) They evaporate faster.

A

c) They form more spherical droplets.

56
Q

What are adhesive forces?

a) Intermolecular forces within the same type of molecules.
b) Intermolecular forces between different molecules.
c) Forces that reduce boiling points.
d) Forces that prevent evaporation.

A

b) Intermolecular forces between different molecules.

57
Q

What does vaporization involve?

a) Forming hydrogen bonds between molecules.
b) Breaking intramolecular forces.
c) Separating intermolecular forces.
d) Increasing cohesive forces.

A

c) Separating intermolecular forces.

58
Q

How can molecules vaporize?

a) By decreasing kinetic energy and temperature.
b) By increasing kinetic energy and temperature.
c) By strengthening hydrogen bonds.
d) By reducing adhesive forces.

A

b) By increasing kinetic energy and temperature.

59
Q

Why does water have a higher boiling point?

a) It has strong dispersion forces.
b) It contains hydrogen bonds that require more energy to break.
c) It has weak cohesive forces.
d) It has high adhesive forces with nonpolar molecules.

A

b) It contains hydrogen bonds that require more energy to break.

60
Q

What happens to molecules that evaporate?

a) They break intramolecular forces.
b) They move fast enough to break the liquid’s surface tension.
c) They form new hydrogen bonds with the air.
d) They decrease the temperature of the liquid.

A

b) They move fast enough to break the liquid’s surface tension.

61
Q

What does the Clausius-Clapeyron equation relate?

a) The boiling point of a liquid and its cohesive forces.
b) The change in heat of vaporization and vapor pressures at two temperatures.
c) The viscosity of a liquid and its temperature.
d) The surface tension and cohesive forces of a liquid.

A

b) The change in heat of vaporization and vapor pressures at two temperatures.

62
Q

When using the Clausius-Clapeyron equation, which conversions must you remember?

a) Convert Kelvin to Celsius and Joules to kilojoules.
b) Convert Celsius to Kelvin and kilojoules to Joules.
c) Convert Kelvin to Celsius and kilojoules to calories.
d) Convert Celsius to Kelvin and Joules to calories.

A

b) Convert Celsius to Kelvin and kilojoules to Joules.

63
Q

Using the Clausius-Clapeyron equation, if the temperature of water increases from 25°C to 58°C (ΔHvap = 44.01 kJ/mol), what is the new vapor pressure at 58°C if the initial pressure at 25°C is 1 atm?

a) 3.50 atm
b) 4.72 atm
c) 5.89 atm
d) 6.20 atm

A

c) 5.89 atm

64
Q

Adhesive forces are responsible for which of the following phenomena?

a) The formation of spherical droplets.
b) Liquids sticking to the walls of a container.
c) Increased viscosity in a liquid.
d) Increased boiling points due to hydrogen bonding.

A

b) Liquids sticking to the walls of a container.

65
Q

What is required for molecules to vaporize?

a) Decreased cohesive forces.
b) Increased adhesive forces.
c) Increased kinetic energy through heating.
d) Formation of new intramolecular bonds.

A

c) Increased kinetic energy through heating.

66
Q

Why does water evaporate slower than alcohol at the same temperature?

a) Alcohol has weaker hydrogen bonding than water.
b) Water has stronger adhesive forces with air.
c) Alcohol has a higher surface tension.
d) Water has a lower boiling point.

A

a) Alcohol has weaker hydrogen bonding than water.

67
Q

The predominant intermolecular force found in Na⁺(aq) is _____

ionic bonds
dipole-dipole interactions
ion-dipole interactions
dispersion forces
covalent bonds

A

ion-dipole interactions

For Na+(aq)(an aqueous solution of sodium cations), the two species that are present are Na⁺ ions and water molecules. Since
Na+ is an ion, and since water has a dipole, this system will exhibit ion-dipole interactions.

68
Q

Which is predicted to have the lowest vapor pressure?

CH4
SiH4
NH3
PH3
H2O

A

H2O

Vapor pressure describes the amount of a liquid that can escape into the gas phase, so compounds with stronger intermolecular forces will have lower vapor pressures. Two of these options exhibit hydrogen bonding (NH3 and H2O). The dipole created by the more electronegative O atom makes the intermolecular forces stronger in H2O, meaning it will have the lower vapor pressure.

69
Q

Which of the following substances is a liquid at room temperature?

CH3CH3
CH3OH
CH4
HCl
CF4

A

CH3OH

The phase of a chemical compound depends on the strength of its intermolecular forces, with strong intermolecular forces resulting in greater attractions and a greater tendency to be in the liquid or solid phase. All of these options exhibit dispersion forces, and some exhibit dipole-dipole forces, but CH3OH is the only compound that exhibits hydrogen bonding (due to its internal O-H bond), meaning it has the strongest intermolecular forces and is most likely to be a liquid.

70
Q

As a pure substance, which of the following could experience dipole-dipole interactions?
I. CO2
II. HCl
III. CCl4

I only
II only
III only
II and III only
I, II, and III

A

II only

All polar molecules experience dipole-dipole interactions. CO2 is a linear symmetrical molecule and is nonpolar. HCl is a linear asymmetrical molecule and is polar. CCl4 is a symmetrical tetrahedral molecule and is nonpolar. Therefore, only HCl (II only) experiences dipole-dipole interactions.

71
Q

As a pure substance? which of the following could experience hydrogen bonding?
I. H2Se
II. H2O
III. H2

II only
III only
I and II
II and III
I, II, and III

A

II only

For hydrogen bonding to be present, a hydrogen atom needs to be bonded to N, O, or F. H2O is the only option that meets that criteria and can form hydrogen bonds.

72
Q

Which of the following represents the intermolecular forces present in CO2?

dispersion only
dipole-dipole only
hydrogen bonding only
dispersion and dipole-dipole
dispersion and hydrogen bonding

A

dispersion only

CO2 has no H atoms. While CO2 has two internal dipoles, they are of equal magnitude and point in opposite directions, meaning they cancel each other out and the molecule has no net dipole moment, so it cannot exhibit dipole-dipole forces.

73
Q

molecules with ____ forces have the lowest freezing points

lowest
highest

74
Q

what term is the measure of energy required to increase the surface tension area of a liquid?

adhesion
capillary action
cohesion
viscosity
surface tension

A

surface tension

75
Q

which best explains why the meniscus of mercury in a glass tube is convex?

the greater attraction of mercury to the lass than to itself

the lower attraction of mercury to the glass than to itself

the low surface tension of mercury

the high density of mercury compared to water

the repulsion between mercury and the glass

A

the lower attraction of mercury to the glass than to itself

76
Q

What does a phase diagram represent?

a) The chemical composition of a substance.
b) The relationship between pressure, temperature, and state of matter.
c) The rate of vaporization of a liquid.
d) The boiling point of water at standard pressure.

A

b) The relationship between pressure, temperature, and state of matter.

77
Q

What occurs at the triple point of a substance?

a) The substance exists only as a gas.
b) The substance exists only as a liquid.
c) All three phases (solid, liquid, gas) coexist in equilibrium.
d) The substance becomes a supercritical fluid.

A

c) All three phases (solid, liquid, gas) coexist in equilibrium.

78
Q

What is the significance of the critical point on a phase diagram?

a) The point where all three phases exist in equilibrium.
b) The temperature and pressure at which the substance can no longer exist as a liquid or gas but becomes a supercritical fluid.
c) The boiling point of the substance at standard pressure.
d) The freezing point of the substance at standard pressure.

A

b) The temperature and pressure at which the substance can no longer exist as a liquid or gas but becomes a supercritical fluid.

79
Q

What effect does increasing pressure have on the boiling point of a liquid?

a) Decreases the boiling point.
b) Increases the boiling point.
c) Has no effect on the boiling point.
d) Causes the liquid to immediately freeze.

A

b) Increases the boiling point.

80
Q

What type of solid is characterized by a highly organized, repeating structure?

a) Crystalline solid
b) Polycrystalline solid
c) Amorphous solid
d) Molecular solid

A

a) Crystalline solid

81
Q

What distinguishes polycrystalline solids from crystalline solids?

a) Polycrystalline solids lack any organized structure.
b) Polycrystalline solids consist of multiple small crystalline regions with different orientations.
c) Polycrystalline solids are always metallic.
d) Polycrystalline solids are better conductors of electricity than crystalline solids.

A

b) Polycrystalline solids consist of multiple small crystalline regions with different orientations.

82
Q

Which of the following is true about amorphous solids?

a) They have a well-defined, repeating structure.
b) They lack long-range order and have no crystalline structure.
c) They are primarily ionic compounds.
d) They are excellent conductors of electricity.

A

b) They lack long-range order and have no crystalline structure.

83
Q

Why are ionic compounds poor conductors of electricity in solid form?

a) Their electrons are delocalized.
b) Their ions are free to move in the lattice.
c) Their ions are held in fixed positions within the lattice.
d) Their intermolecular forces are weak.

A

c) Their ions are held in fixed positions within the lattice.

84
Q

Which type of crystalline solid is composed of metal cations in a sea of delocalized electrons?

a) Covalent crystalline solid
b) Molecular solid
c) Ionic crystalline solid
d) Metallic crystalline solid

A

d) Metallic crystalline solid

85
Q

Which type of crystalline solid is formed by a network of covalent bonds?

a) Ionic crystalline solid
b) Covalent crystalline solid
c) Metallic crystalline solid
d) Molecular solid

A

b) Covalent crystalline solid

86
Q

Which of the following is an example of a molecular crystalline solid?

a) Sodium chloride
b) Ice crystals
c) Diamond
d) Iron

A

b) Ice crystals

87
Q

What intermolecular forces hold molecular solids together?

a) Covalent bonds
b) Ionic bonds
c) Metallic bonds
d) Intermolecular forces such as hydrogen bonding or dispersion forces

A

d) Intermolecular forces such as hydrogen bonding or dispersion forces