Exam 1 True/False Practice

Question 1

Which of the following is/are polar?

CH3OCH3

Answer 1

Polar

Question 2

Which of the following is/are polar?

BrF3

Answer 2

Polar

Question 3

Which of the following is/are polar?

SF6

Answer 3

Nonpolar

Question 4

Which of the following is/are polar?

SO3

Answer 4

Nonpolar

Question 5

Which of the following is/are polar?

C3H8

Answer 5

Nonpolar

Question 6

Which of the following is/are polar?

SO2

Answer 6

Polar

Question 7

Intermolecular forces are within molecules; bonds are
between molecules.

Answer 7

False

Question 8

Bonds are generally weaker than intermolecular forces.

Answer 8

False

Question 9

The strongest intermolecular force in a pure substance is hydrogen bonding.

Answer 9

True

Question 10

Dipole-dipole forces are the result of an instantaneous dipole interacting with an induced dipole.

Answer 10

False

Question 11

Dispersion forces are present between all molecules, but are the only intermolecular force between two non-polar molecules.

Answer 11

True

Question 12

The strongest intermolecular force between two CH3CHO molecules is hydrogen bonding

Answer 12

False

Question 13

The strongest intermolecular force between two silicon tetrafluoride molecules is dipole-dipole forces.

Answer 13

False

Question 14

There are only dipole-dipole forces and dispersion forces between two CH2F2 molecules; there is not hydrogen bonding.

Answer 14

True

Question 15

There should be dipole-dipole forces and dispersion forces between two C6H14 molecules

Answer 15

False

Question 16

The strongest intermolecular force between two helium atoms should be dispersion forces.

Answer 16

True

Question 17

Solids have strong intermolecular forces relative to thermal energy

Answer 17

True

Question 18

Solids can be categorized as crystalline or amorphous; amorphous solids have no long-range order.

Answer 18

True

Question 19

We can change from a liquid to a gas by increasing
temperature or increasing pressure.

Answer 19

False

Question 20

In a liquid, the particles can move with respect to one another, so liquids have an indefinite volume, but definite shape.

Answer 20

False

Question 21

The strongest intermolecular force between two CH3CHO molecules is hydrogen bonding

Answer 21

False

Question 22

The strongest intermolecular force between two silicon tetrafluoride molecules is dipole-dipole forces.

Answer 22

False

Question 23

There are only dipole-dipole forces and dispersion forces between two CH2F2 molecules; there is not hydrogen bonding.

Answer 23

True

Question 24

There should be dipole-dipole forces and dispersion forces between two C6H14 molecules

Answer 24

False

Question 25

The strongest intermolecular force between two helium atoms should be dispersion forces.

Answer 25

True

Question 26

Vaporization is the process of changing a substance from a liquid to a gas

Answer 26

True

Question 27

The rate of vaporization increases with increasing temperature and surface area, but decreasing intermolecular forces

Answer 27

True

Question 28

If a liquid is considered volatile, it is explosive

Answer 28

False

Question 29

Vaporization only occurs at the boiling point of a liquid

Answer 29

False

Question 30

The energy change for vaporization is the same magnitude, but opposite sign as the energy change for condensation

Answer 30

True

Question 31

The boiling point of a liquid is when the vapor pressure of the liquid is equal to the external pressure

Answer 31

True

Question 32

If the pressure above a liquid-vapor system in equilibrium decreases (a disturbance), some of the liquid will evaporate (to minimize the disturbance and restore equilibrium)

Answer 32

True

Question 33

Dynamic equilibrium is reached when the condensation and vaporization processes stop

Answer 33

False

Question 34

If you bring a pot of water from sea level to La Paz, Bolivia (11,975 ft above sea level), you will increase its boiling point

Answer 34

False

Question 35

Another word for fusion is freezing

Answer 35

False

Question 36

Fusion is an endothermic process, so the enthalpy of fusion is positive

Answer 36

True

Question 37

Heating a liquid in a closed container until its temperature is beyond the critical temperature produces a supercritical fluid

Answer 37

True

Question 38

An ice cube slowly disappearing from an ice cube tray in a freezer is an example of sublimation

Answer 38

True

Question 39

There is no change in temperature when energy is added to a block of ice at its freezing point until all the ice has melted

Answer 39

True

Question 40

Enthalpy of fusion generally decreases with increasing strength of intermolecular forces

Answer 40

False

Question 41

solution that contains more dissolved solute than the equilibrium amount is supersaturated

Answer 41

True

Question 42

Solubility of most solids decreases with increasing temperature

Answer 42

False

Question 43

Solubility of most gases increases with increasing pressure and temperature.

Answer 43

False

Question 44

An unsaturated solution contains less than the equilibrium amount of solute

Answer 44

True

Question 45

solution in which the dissolved solute is in dynamic equilibrium with the solid (undissolved) solute is a saturated solution

Answer 45

True

Question 46

When a solution forms, the solute-solute interactions must be overcome, so ΔHsolute is endothermic

Answer 46

True

Question 47

When a solution forms, the solvent-solvent interactions must be overcome, so ΔHsolvent is endothermic

Answer 47

True

Question 48

ΔHmix is endothermic

Answer 48

False

Question 49

The heat of hydration is the enthalpy change that occurs when 1 mole of the gaseous solute ions are dissolved in water; it is always largely negative (exothermic) for ionic compounds

Answer 49

True

Question 50

Colligative properties depend on the number of particles dissolved in solution, not on the type of particles

Answer 50

True

Question 51

Vapor pressure increases as the mol fraction of solute dissolved in the solvent increases

Answer 51

False

Question 52

Dissolving a nonvolatile solute into a solvent decreases its vapor pressure

Answer 52

True

Question 53

If the solute is volatile, it also contributes to the overall vapor pressure of the solution

Answer 53

True

Question 54

0.02 M FeBr3 solution will have the same osmotic pressure as a 0.02 M AlCl3 solution, assuming ideal Van Hoff factors.

Answer 54

True

Question 55

An aqueous 0.03 m NaCl solution will have a higher boiling point than an aqueous 0.04 m C6H12O6 (glucose) solution, assuming ideal Van Hoff factors.

Answer 55

True

Question 56

The measured Van Hoff factor can be larger than the ideal when there is ion pairing.

Answer 56

False

Question 57

An aqueous 0.02 m HCl solution will have a higher boiling point than an aqueous 0.02 m HF (a weak acid) solution.

Answer 57

True

Question 58

According to collision theory, rate of reaction increases with decreasing temperature because more particles have enough energy to overcome the activation energy

Answer 58

False

Question 59

According to collision theory, rate of reaction increases with increasing concentration because particles are more likely to collide with one another

Answer 59

True

Question 60

For the reaction 2 A + B + C –> 3 D + E, if the rate at an instant in time is –0.12 M/s for A, then the rate for D is +0.08 M/s.

Answer 60

False

Question 61

Rate of reaction generally decreases with time.

Answer 61

True

Question 62

For the reaction A –> B + 2C where the reaction is determined to be first order, if the initial rate is 0.01 M/s when [A] = 0.10 M, then the initial rate will be 0.02 M/s when [A] = 0.20 M.

Answer 62

True

Question 63

For the reaction A –> 2 B where the reaction is determined to be second order, if the initial rate is 0.001 M/s when [A] = 0.10 M, then the initial rate will be 0.016 M/s when [A] = 0.40 M.

Answer 63

True

Question 64

For the reaction A –> B where the reaction is determined to be zero order, if the initial rate is 0.1 M/s when [A] = 2.0 M, then the initial rate will be 0.2 M/s when [A] = 4.0 M.

Answer 64

False

Question 65

For the reaction A + B + 2 C –> 3 D + E, if the rate law is Rate = k [A][C], then the overall order of the reaction is 4.

Answer 65

False

Question 66

The integrated rate law shows how the rate depends on concentration; the differential rate law shows how concentration depends on time

Answer 66

False

Question 67

In the integrated rate law, k is the same rate constant as in the differential rate law

Answer 67

True

Question 68

The rate law (differential rate law) must be determined experimentally; the integrated rate law is derived from the rate law mathematically

Answer 68

True

Question 69

When the inverse of the concentration of reactant X is plotted vs time, a straight line will result if the reaction is zero-order in X

Answer 69

False

Question 70

When the natural log of the concentration of a reactant X is plotted vs time, a straight line will result if the reaction is first-order in X

Answer 70

True

Question 71

The first half-life for the reaction 2A -> A2 is 20 seconds. The second half-life is 10 seconds. This reaction is second order.

Answer 71

False

Question 72

The first half-life for the reaction 2B -> B2 is 20 seconds. The second half-life is 40 seconds. This reaction is zero order.

Answer 72

False

Question 73

The first half-life for the reaction 2C -> C2 is 15 seconds. Each half-life thereafter is 15 seconds. This reaction is first order.

Answer 73

True