Deck 12: Solutions

Question 1

In general,which of the following type(s)of solid(s)would exhibit the greatest solubility in a polar solvent?

A)network covalent
B)ionic or polar molecular
C)ionic
D)metallic
E)polar molecular

Answer 1

ionic or polar molecular

Question 2

Which of the following gases is least soluble in water?

A)CO₂
B)SO₃
C)NH₃
D)N₂
E)HCl

Answer 2

N₂

Question 3

Henry's Law constant is 0.034 mol/kg⋅bar and 0.0013 mol/kg⋅bar for CO₂ and O₂ respectively at 25°C.What pressure of O₂ is required to achieve the same solubility as 0.368 bar of CO₂?

A)9.6 bar
B)0.0 bar
C) bar
D) bar
E)0.1 bar

Answer 3

9.6 bar

Question 4

Which of the following favor(s)the solubility of an ionic solid in a liquid solvent?

A)a small magnitude of the lattice energy of the solute
B)a large magnitude of the solvation energy of the ions
C)a large polarity of the solvent
D)all of the above
E)none of the above

Question 5

The solubility of 1-pentanol in water is 2.7 g per 100 g of water at 25°C.What is the maximum amount of 1-pentanol that will dissolve in 4.1g of water at 25°C?

A)0.11 g
B)0.65 g
C)2.7 g
D)11 g
E)0.0065 g

Question 6

Which of the following is a correct statement of Henry's law?

A)The concentration of a gas in solution is directly proportional to the mole fraction of solvent.
B)The concentration of a gas in solution is inversely proportional to temperature.
C)The concentration of a gas in solution is independent of pressure.
D)The concentration of a gas in a solution is inversely proportional to pressure.
E)none of these

Question 7

Which of the following statements best describes what happens when a small amount of solid rubidium chloride is dissolved in water?

A)The heat from the warm water melts the solid,making it a liquid.
B)Nothing happens,because rubidium chloride is insoluble in water.
C)The solid RbCl breaks apart into separate Rb and Cl atoms by interacting with the water molecules.
D)The water molecules surround each ion in the solid RbCl,separating the Rb ions from the Cl ions.
E)The solid undergoes a chemical change by reacting with the water.

Question 8

Which of the following compounds is least soluble in water?

A)CH₃CH₂CH₂NH₂
B)CH₃CH₂CH₂F
C)CH₃CH(OH)CH₃
D)CH₃CH₂COOH
E)CH₃CH₂NHCH₃

Question 9

According to the National Institute of Standards webbook,the Henry's Law constant for N₂ gas is 0.000639 mol/kg⋅bar at 25°C What is the Henry's law constant in units of mol/kg⋅atm? (1 bar = 0.9869 atm; 1 atm = 760 mmHg)

A) × 10^-4 mol/kg⋅atm
B) × 10^-7 mol/kg⋅atm
C) × 10^-1 mol/kg⋅atm
D) × 10³ mol/kg⋅atm
E) × 10⁶ mol/kg⋅atm

Question 10

Consider the following gas-aqueous liquid equilibrium for a closed system at a constant temperature.
O₂(g) O₂(aq)
What is the effect on the equilibrium composition of the liquid when the partial pressure of O₂ gas above the liquid is decreased?

A)The amount of O₂ dissolved in the liquid decreases.
B)The amount of O₂ dissolved in the liquid increases.
C)The amount of O₂ dissolved in the liquid does not change.
D)Not enough information is provided to answer the question.
E)Either A or B.

Question 11

Consider the following gas-liquid equilibrium for an aqueous system at a constant partial pressure of N₂.
N₂(g)
N₂(aq)
What is the effect on the equilibrium composition of the liquid when the temperature of the liquid is increased?

A)The amount of N₂ dissolved in the liquid increases.
B)The amount of N₂ dissolved in the liquid decreases.
C)The amount of N₂ dissolved in the liquid does not change.
D)Not enough information is provided to answer the question.
E)Either A or B could occur.

Question 12

Which of the following correctly states the relationship between the solubility of a substance in water and temperature?

A)The solubility of a substance in water increases as the temperature rises,especially for gases.
B)The solubility of a substance in water decreases as the temperature lowers,especially for gases.
C)The relationship between the solubility of a substance in water and temperature cannot be accurately predicted,especially for ionic solids.
D)The solubility of a substance in water decreases as the temperature rises,especially for ionic solids.
E)Two of these are correct.

Question 13

Which of the following sets of conditions favors maximum solubility of an ionic solute in water?

A)The enthalpy of hydration of the cation should be equal to the enthalpy of hydration of the anion,regardless of the magnitude of the lattice energy.
B)The magnitude of the lattice energy should be small,and the enthalpy of hydration of the ions should be large.
C)The magnitude of the lattice energy should be small,and the enthalpy of hydration of the ions should be small.
D)The magnitude of the lattice energy should be large,and the enthalpy of hydration of the ions should be small.
E)The magnitude of the lattice energy should be large,and the enthalpy of hydration of the ions should be large.

Question 14

At a particular temperature the solubility of O₂ in water is 0.590 g/L at an oxygen pressure of around 15.2 atm.What is the Henry's law constant for O₂ (in units of L · atm/mol)?

A)3.88 × 10^-2
B)8.24 × 10²
C)2.80× 10^-1
D)1.21× 10^-3
E)None of the above are within 5% of the correct answer.

Question 15

Which of the following pure liquids is the best solvent for sodium fluoride?

A)CCl₄(l)
B)C₂Cl₆(l)
C)HCl(l)
D)BCl₃(l)
E)PCl₅(l)

Question 16

Which of the following sets of conditions favors maximum solubility of solute in solvent?

A)The intermolecular forces between solute and solvent molecules are much weaker than the intermolecular forces between solute molecules,but much stronger than the intermolecular forces between solvent molecules.
B)The intermolecular forces between solute and solvent molecules are much stronger than the intermolecular forces between solute molecules or the intermolecular forces between solvent molecules.
C)The intermolecular forces between solute and solvent molecules are much stronger than the intermolecular forces between solvent molecules,but much weaker than the intermolecular forces between solute molecules.
D)The intermolecular forces between solute and solvent molecules are much stronger than the intermolecular forces between solute molecules,but much weaker than the intermolecular forces between solvent molecules.
E)The intermolecular forces between solute and solvent molecules are much weaker than the intermolecular forces between solute molecules or the intermolecular forces between solvent molecules.

Question 17

Which of the following pure liquids is the best solvent for carbon disulfide?

A)C₆H₆(l)
B)NH₃(l)
C)CH₃OH(l)
D)H₂O(l)
E)HBr(l)

Question 18

The solubility of a gas in a liquid can always be increased by

A)decreasing the pressure of the gas above the solvent.
B)increasing the pressure of the gas above the solvent.
C)increasing the temperature of the solvent.
D)decreasing the polarity of the solvent.
E)decreasing the temperature of the gas above the solvent.

Question 19

The dissolution of ionic compounds in water depends only on the hydration energy of the ions.

A)1 only
B)2 only
C)3 only
D)1 and 2
E)1,2,and 3

Question 20

How does the solubility of a gas in a solvent depend on pressure and temperature?

A)Increasing the partial pressure of the gas while increasing the temperature increases the solubility of the gas.
B)Decreasing the partial pressure of the gas while decreasing the temperature increases the solubility of the gas.
C)Increasing the partial pressure of the gas while decreasing the temperature increases the solubility of the gas.
D)Decreasing the partial pressure of the gas while increasing the temperature increases the solubility of the gas.
E)Gas solubility is unaffected by pressure or temperature.

Question 21

What is the mass percent of an aqueous sodium hydroxide solution in which the molality of NaOH is 10.7 m? The density of the solution is 1.3311 g/mL.

A)0.1%
B)68.9%
C)1.7%
D)30.0%
E)0.3%

Question 22

The molarity of a solution is defined as the

A)moles of solute per liter of solvent.
B)grams of solute per kilogram of solvent.
C)grams of solute per liter of solution.
D)moles of solute per liter of solution.
E)moles of solute per kilogram of solvent.

Question 23

If the solubility of O₂ at 0.160 bar and 25°C is 6.65 g/100 g H₂O,what is the solubility of O₂ at a pressure of 1.84 bar and 25°C?

A)77 g/100 g H₂O
B)22.5 g/100 g H₂O
C)1.7 g/100 g H₂O
D)0.0 g/100 g H₂O
E)0.6 g/100 g H₂O

Question 24

What mass of an aqueous 33.7% sodium chloride solution contains 88.1 g of water?

A)132 g
B)44.7 g
C)11.9 g
D)29.6 g
E)88.1 g

Question 25

The volume of a 34.6% (by mass)solution is 129.0 mL.The density of the solution is 1.116 g/mL.What is the mass of solute in this solution?

A)144 g
B)49.8 g
C)416 g
D)40.0 g
E)94 g

Question 26

What is the molarity of a 10.0% by mass hydrochloric acid solution? The density of the solution is 1.0474 g/mL.

A)7 M
B)0 M
C)9 M
D)3 M
E)1 M

Question 27

A concentrated acetic acid solution has a density of 1.05 g/mL at 25°C and is 17.4 M.What is the percent by mass of CH₃COOH in the solution?

A)99.5% CH₃COOH by mass
B)1.7% CH₃COOH by mass
C)0.6% CH₃COOH by mass
D)2.8% CH₃COOH by mass
E)57.1% CH₃COOH by mass

Question 28

What is the mass percent of an aqueous sodium hydroxide solution in which the mole fraction of NaOH is 0.1010? The density of the solution is 1.2219 g/mL.

A)20.0%
B)12.0%
C)68.9%
D)12.3%
E)3.3%

Question 29

A concentrated sulfuric acid solution is 65.0% H₂SO₄ by mass and has a density of 1.55 g/mL at 20°C.What is the mass of 9.00 L of the concentrated sulfuric acid solution?

A)5.85 kg
B)9.00 kg
C)21.4 kg
D)3.77 kg
E)13.9 kg

Question 30

Which of the following is not a colligative property?

A)boiling-point elevation
B)osmotic pressure
C)lattice energy
D)freezing-point lowering
E)vapor-pressure lowering

Question 31

The molarity of a solution is defined as the

A)moles of solute per liter of solvent.
B)moles of solute per kilogram of solution.
C)moles of solute per mole of solution.
D)moles of solute per kilogram of solvent.
E)moles of solute per liter of solution.

Question 32

The molality of a solution is defined as

A)moles of solute per liter of solution.
B)the gram molecular weight of solute per kilogram of solvent.
C)moles of solute per kilogram of solvent.
D)grams of solute per liter of solution.
E)moles of solute per kilogram of solution.

Question 33

What is the mass of H₂SO₄ in a 38.2-cm³ sample of concentrated sulfuric acid that has a density of 1.84 g/cm³ and consists of 98.3% H₂SO₄?

A)37.6 g
B)69.1 g
C)4.73 g
D)1.81 g
E)20.4 g

Question 34

What is the percent Na₂CO₃ by mass in a 1.92 molal aqueous solution?

A)0.160%
B)16.9%
C)99.5%
D)20.4%
E)19.2%

Question 35

What is the mass percent of an aqueous sodium hydroxide solution in which the molarity of NaOH is 9.98 M? The density of the solution is 1.33 g/mL.

A)0.1%
B)30.0%
C)13.2%
D)1.7%
E)68.9%

Question 36

As the number of solute particles in a given volume of solution increases,

A)the boiling point will increase and the vapor pressure will increase.
B)the freezing point will decrease and the vapor pressure will decrease.
C)the freezing point will increase and the vapor pressure will increase.
D)the boiling point will decrease and the vapor pressure will decrease.
E)the osmotic pressure will decrease and the lattice energy will increase.

Question 37

The volume of a 24.0% (by mass)solution is 65.2 mL.The density of the solution is 1.072 g/mL.What is the mass of the solution?

A)69.8 g
B)61 g
C)1670 g
D)167 g
E)17 g

Question 38

What mass of a 29.0% by mass glucose,C₆H₁₂O₆,solution contains 60.0 g of glucose?

A)52.2 g
B)207 g
C)17.4 g
D)96.7 g
E)60.0 g

Question 39

A concentrated hydrofluoric acid solution is 49.0% HF by mass and has a density of 1.3406 g/mL at 25°C.What is the mass of HF per L of solution?

A)637 g HF /L soln
B)0.0013 g HF /L soln
C)376 g HF /L soln
D)0.265 g HF /L soln
E)3.76 g HF /L soln

Question 40

A concentrated sodium hydroxide solution is 50.5% NaOH by mass and has a density of 1.53 g/mL at 25°C.What is the molarity of NaOH?

A)19.3 M
B)0.0612 M
C)8.25 M
D)12.1 M
E)0.0825 M

Question 41

How many moles of urea (60.g/mol)must be dissolved in 66.6g of water to give a 2.4 m solution?

A)1.4 × 10² mol
B)2.4 mol
C)0.0024 mol
D)0.15 mol
E)9.0 × 10² mol

Question 42

A concentrated ammonia solution is 28.0% NH₃ by mass and has a density of 0.939 g/mL at 25°C.The remainder of material is solvent.What is the molality of NH₃ in the solution?

A)22.8 m
B)16.4 m
C)12.8 m
D)437 m
E)0.236 m

Question 43

What mass of a solution labeled 6.3% sucrose (C₁₂H₂₂O₁₁,342 g/mol)by mass contains 11.0 g of sucrose?

A)2.7 g
B)21 g
C)170 g
D)0 g
E)69 g

Question 44

What is the molality of ethanol,C₂H₅OH,in an aqueous solution that is 36.4% ethanol by mass?

A)1 m
B)0 m
C)12 m
D)19 m
E)97 m

Question 45

What is the mole fraction of urea in a solution that contains 2.7 mol of urea and 4.6 mol of water?

A)0.77
B)0.37
C)0.47
D)0.57
E)0.63

Question 46

What is the mole fraction of urea,CO(NH₂)₂,in a solution prepared by dissolving 4.0 g of urea in 32.0 g of methanol,CH₃OH?

A)0.89
B)0.11
C)0.063
D)0.94
E)0.19

Question 47

What is the molality of a solution that contains 9.16 g of glucose,C₆H₁₂O₆,in 228.5 g of water?

A)0.223 m
B)0.0509 m
C)0.00399 m
D)0.0116 m
E)0.0401 m

Question 48

What is the mole fraction of water in a solution that contains 8.0 mol of ethanol (C₂H₅OH)and 1.6 mol of water?

A)0.17
B)0.08
C)0.50
D)0.20
E)0.83

Question 49

What is the mole fraction of urea,CH₄N₂O,in an aqueous solution that is 37% urea by mass?

A)0.15
B)0.85
C)0.37
D)0.54
E)0.66

Question 50

If 11.2 g of naphthalene,C₁₀H₈,is dissolved in 107.8 g of chloroform,CHCl₃,what is the molality of the solution?

A)0.0875 m
B)12.4 m
C)0.811 m
D)0.0941 m
E)0.0969 m

Question 51

What is the mole fraction of toluene in a solution of 2.7 mol of benzene and 5.4 mol of toluene?

A)0.70
B)0.54
C)0.67
D)0.24
E)0.33

Question 52

What is the mole fraction of water in a water-ethanol solution that is 47.0% water by mass? (Ethanol is C₂H₅OH.)

A)0.28
B)0.31
C)0.26
D)0.69
E)0.53

Question 53

What is the molality of a solution prepared by dissolving 0.114 mol of chloroform,CHCl₃,in 476 g of toluene,C₆H₅CH₃?

A)0.0287 m
B)0.0216 m
C)0.239 m
D)0.0220 m
E)0.543 m

Question 54

What is the molality of a solution that contains 74.2 g of 1,4-dichlorobenzene (C₆H₄Cl₂)in 492 mL of carbon tetrachloride (CCl₄)? The density of CCl₄ is 1.60 g/mL.

A)0.158 m
B)0.642 m
C)0.151 m
D)0.094 m
E)1.64 m

Question 55

For a solution containing only one solute dissolved in a solvent,we can calculate the mole fraction of the solvent directly,given only

A)the molar mass of the solute.
B)the density of the solution.
C)the molar mass of the solvent.
D)the mole fraction of the solute.
E)the molarity of the solution.

Question 56

What is the molality of a solution prepared by dissolving 9.01 g of urea,NH₂CONH₂,in 93.8 g of water?

A)0.0876 m
B)0.096498 m
C)0.028985 m
D)1.59 m
E)0.00145 m

Question 57

What is the molality of a 30.0% by mass hydrochloric acid solution? The density of the solution is 1.1493 g/mL.

A)0.0344 m
B)11.7 m
C)0.377 m
D)9.29 m
E)9.45 m

Question 58

Which way of expressing concentration is used to relate the vapor pressure of a solution to the amount of nonvolatile solute dissolved in the solution?

A)mole fraction
B)molarity
C)osmotic pressure
D)mass percent
E)molality

Question 59

A 3.140 molal solution of NaCl is prepared.How many grams of NaCl are present in a sample containing 2.692 kg of water?

A)299.7 g
B)494.0 g
C)144.6 g
D)845.3 g
E)none of these

Question 60

A 12.0% sucrose solution by mass has a density of 1.05 g/cm³.What mass of sucrose is present in a 29.0-mL sample of this solution?

A)3.65 g
B)3.31 g
C)0.126 g
D)253 g
E)3.48 g

Question 61

If a 23.6-g sample of a nonelectrolyte is dissolved in 136.0 g of water,the resulting solution will freeze at -0.85°C.What is the molar mass of the nonelectrolyte? (K_f for water is 1.858°C/m.)

A)78 g/mol
B)0.38 g/mol
C)870 g/mol
D)270 g/mol
E)370 g/mol

Question 62

Trimellitic acid is an organic acid that has a composition of 51.44% C,2.88% H,and 45.68% O by mass.A 6.96-g sample of trimellitic acid dissolved in 30.00 g of acetone,CH₃COCH₃,has a boiling point of 58.09°C.What is the molecular formula of trimellitic acid? (K_b for acetone is 1.71°C/m,and pure acetone has a boiling point of 56.20°C.)

A)CH₂O
B)C₉H₆O₆
C)C₃HO₂
D)C₁₈HO₁₆
E)C₆H₂O₄

Question 63

A liquid-liquid solution is called an ideal solution if
I.it obeys PV = nRT.
II.it obeys Raoult's law.
III.solute-solute,solvent-solvent,and solute-solvent interactions are very similar.
IV.solute-solute,solvent-solvent,and solute-solvent interactions are quite different.

A)I,III,IV
B)I,II,III
C)II,III only
D)I,II,IV
E)II,IV only

Question 64

What is the mass percent of ethylene glycol (HOCH₂CH₂OH)in a solution of ethylene glycol in water that has a freezing point of -17.8°C? (K_f for water is 1.858°C/m.)

A)99.8%
B)37.2%
C)59.4%
D)64.7%
E)9.58%

Question 65

What is the vapor pressure at 75°C of an aqueous solution prepared by the addition of 58.4 g of the nonvolatile solute urea,CO(NH₂)₂,to 172 g of water? The vapor pressure of pure water at 75°C is 290.mmHg.

A)136 mmHg
B)26.8 mmHg
C)153 mmHg
D)263 mmHg
E)216 mmHg

Question 66

What is the molar mass of an aromatic hydrocarbon if 0.75 g of the compound depresses the freezing point of 123 g of benzene by 0.28°C? (K_f for benzene is 5.12°C/m.)

A)43 g/mol
B)150 g/mol
C)110.00 g/mol 110
D)2900 g/mol
E)140 g/mol

Question 67

Thyroxine,an important hormone that controls the rate of metabolism in the body,can be isolated from the thyroid gland.If 0.454 g of thyroxine is dissolved in 10.0 g of benzene,the freezing point of the solution could be measured as 5.144°C.Pure benzene freezes at 5.444°C and has a value for the molal freezing-point-depression constant of K_f of 5.12°C/m.What is the approximate molar mass of thyroxine?

A)775 g/mol
B)7.75 g/mol
C)7.75 × 10⁵ g/mol
D)42.7 g/mol
E)11.3 g/mol

Question 68

Substance A has a greater molar mass than substance B.If 50 g of substance A are dissolved in 250 g of water in one beaker,and 50 g of substance B are dissolved in 250 g of water in another beaker,then

A)the vapor pressure of solution A will be lower than the vapor pressure of solution B.
B)the solution of A will freeze at a lower temperature than the solution of B.
C)the two solutions will have the same vapor pressure.
D)the boiling point of solution A will be lower than the boiling point of solution B.
E)the solution of A will have a higher osmotic pressure than the solution of B.

Question 69

What is the freezing point of a 0.19 m solution of glucose,C₆H₁₂O₆,in water? (K_f for water is 1.858°C/m.)

A)0.18°C
B)0.35°C
C)-0.35°C
D)-0.18°C
E)-0.71°C

Question 70

What is the vapor pressure at 20°C of an ideal solution prepared by the addition of 1.36 g of the nonvolatile solute urea,CO(NH₂)₂,to 24.1 g of methanol,CH₃OH? The vapor pressure of pure methanol at 20°C is 89.0 mmHg.

A)2.6708 mmHg
B)80.4 mmHg
C)84.2 mmHg
D)86.3 mmHg
E)8.51 mmHg

Question 71

What is the boiling-point change for a solution containing 0.723 mol of naphthalene (a nonvolatile,nonionizing compound)in 250.g of liquid benzene? (K_b = 2.53°C/m for benzene)

A)7.32 °C
B)3.50 °C
C)0.457 °C
D)0.87 °C
E)1.829 °C

Question 72

Benzene,C₆H₆,and toluene,C₆H₅CH₃,form ideal solutions.At 35°C the vapor pressure of benzene is 160.torr and that of toluene is 50.0 torr.In an experiment,55.6 g of benzene and 86.6 g of toluene are placed in a closed container at 35°C.At equilibrium,what is the partial vapor pressure of toluene?

A)103 torr
B)91.634 torr
C)21.5 torr
D)68.9 torr
E)28.4 torr

Question 73

A solution of CF₃H in H₂CO is most likely to

A)be ideal.
B)not be ideal,but the deviations cannot be predicted.
C)show negative deviations from Raoult's law.
D)obey Raoult's law.
E)show positive deviations from Raoult's law.

Question 74

Which of the following methods cannot be used to determine the molar mass of a nonelectrolyte?

A)measurement of the freezing-point depression of a solution of the compound
B)measurement of the boiling-point elevation of a solution of the compound
C)measurement of the pressure,temperature,volume,and mass of the compound in the gaseous state
D)measurement of the x-ray diffraction of a pure crystal of the compound
E)measurement of the osmotic pressure of a solution of the compound

Question 75

A solution consisting of 0.276 mol of methylbenzene,C₆H₅CH₃,in 242 g of nitrobenzene,C₆H₅NO₂,freezes at -2.0 °C.Pure nitrobenzene freezes at 6.0°C.What is the freezing-point depression constant of nitrobenzene?

A)7.2°C/m
B)29°C/m
C)14.0°C/m
D)3.5°C/m
E)7.0°C/m

Question 76

Benzene,C₆H₆,and toluene,C₆H₅CH₃,form ideal solutions.At 35°C the vapor pressure of benzene is 160.torr and that of toluene is 50.0 torr.In an experiment,3.9 mol of benzene and 5.7 mol of toluene are placed in a closed container at 35°C and allowed to come to equilibrium.What is the mole fraction of toluene in the vapor phase?

A)0.52
B)0.69
C)0.31
D)0.12
E)0.60

Question 77

When 1 mol of a nonvolatile nonelectrolyte is dissolved in 3 mol of a solvent,the vapor pressure of the solution compared with that of the pure solvent is

A)1/4.
B)4/5.
C)1/2.
D)1/5.
E)3/4.

Question 78

A solute added to a solvent raises the boiling point of the solution because

A)the temperature to cause boiling must be great enough to boil not only the solvent but also the solute.
B)the solute particles raise the solvent's vapor pressure,thus requiring a higher temperature to cause boiling.
C)the solute increases the volume of the solution,and an increase in volume requires an increase in the temperature to reach the boiling point (derived from PV = nRT).
D)the solute particles lower the solvent's vapor pressure,thus requiring a higher temperature to cause boiling.
E)two of these explanations are correct.

Question 79

The fact that the boiling point of a pure solvent is lower than the boiling point of a solution of the same solvent is a direct consequence of the

A)freezing-point depression of the solution.
B)vapor pressure of the solution being higher than the vapor pressure of the pure solvent.
C)osmotic pressure of the solvent being lower than the osmotic pressure of the solution.
D)vapor pressure of the solution being lower than the vapor pressure of the pure solvent.
E)osmotic pressure of the solvent being higher than the osmotic pressure of the solution.

Question 80

A solution of two liquids,A and B,shows negative deviation from Raoult's law.This means that

A)the two liquids have a positive heat of solution.
B)molecules of A interact more strongly with B than A molecules interact with A or B molecules interact with B.
C)molecules of A interact strongly with other A-type molecules.
D)molecules of A interact weakly,if at all,with B molecules.
E)molecules of A hinder the strong interaction between B molecules.