Question 1

Which one of the following substances would be the least soluble in CCl₄? A)CH₃CH₂OH B)H₂O C)NH₃ D)C₁₀H₂₂ E)NaCl

Accepted Answer

Since CCl4 is a nonpolar solvent, it can only dissolve nonpolar or slightly polar substances. Among the given substances, NaCl is an ionic compound and is therefore highly polar, making it insoluble in CCl4.

Question 2

Which of the following substances is more likely to dissolve in water? A)HOCH₂CH₂OH B)CHCl₃ C)O  CH₃(CH₂)₉CH D)CH₃(CH₂)₈CH₂OH E)CCl₄

Accepted Answer

A

Question 3

The principal reason for the extremely low solubility of NaCl in benzene (C₆H₆)is the __________. A)strong solvent-solvent interactions B)hydrogen bonding in C₆H₆ C)strength of the covalent bond in NaCl D)weak solvation of Na⁺ and Cl^- by C₆H₆ E)increased disorder due to mixing of solute and solvent

Accepted Answer

The weak solvation of Na+ and Cl- ions by nonpolar benzene molecules is the principal reason for the extremely low solubility of NaCl in benzene. The strong ionic bonding in NaCl does not allow for easy dissolution in a nonpolar solvent like benzene. Hydrogen bonding and covalent bonding are not relevant factors in this case. Increased disorder due to mixing of solute and solvent may contribute to entropy-driven solubility, but is not the principal reason for the extremely low solubility observed in this case.

Question 4

When two nonpolar organic liquids are mixed, a solution forms and the enthalpy of solution is quite small. Label the two organic liquids as A (solvent)and B (solute). The formation of solution is favored by __________.
A)hydration of the solute, B
B)the equal enthalpy of the solvent and solute
C)the highly negative enthalpy of the solution process
D)solvation of the solvent, A
E)an increase in disorder, since A-A, B-B, and A-B interactions are similar

Accepted Answer

The formation of solution is favored when there is an increase in disorder, which is promoted by similar A-A, B-B, and A-B interactions in nonpolar organic liquids. The enthalpy of solution is small because the solute-solvent interactions are weak due to nonpolar nature, and the enthalpy of the solution process is not highly negative. There is no hydration of solute as both solvents are nonpolar. Solvation of the solvent does occur but is not the primary driving force for the formation of a solution.

Question 5

Compounds composed of a salt and water combined in definite proportions are known as
A)clathrates
B)homogenates
C)ionic solids
D)molecular solids
E)hydrates

Accepted Answer

Compounds composed of a salt and water combined in definite proportions are known as hydrates.

Question 6

Formation of solutions where the process is endothermic can be spontaneous provided that __________.
A)they are accompanied by another process that is exothermic
B)they are accompanied by an increase in order
C)they are accompanied by an increase in disorder
D)the solvent is a gas and the solute is a solid
E)the solvent is water and the solute is a gas

Accepted Answer

An endothermic process can be spontaneous if it results in an increase in disorder (entropy), as the overall change in free energy (Gibbs free energy) can still be negative.

Question 7

When argon is placed in a container of neon, the argon spontaneously disperses throughout the neon because __________.
A)of the large attractive forces between argon and neon atoms
B)of hydrogen bonding
C)a decrease in energy occurs when the two mix
D)the dispersion of argon atoms produces an increase in disorder
E)of solvent-solute interactions

Accepted Answer

This is an application of the second law of thermodynamics, which states that any spontaneous process in a closed system will result in an increase in entropy or disorder. When argon is placed in a container of neon, the argon atoms will spontaneously disperse throughout the neon atoms, resulting in an increase in disorder. This is due to the fact that the argon and neon atoms have similar sizes, and there are no strong attractive forces between them to prevent the mixing. Therefore, the best answer is D, as there are no solvent-solute interactions or hydrogen bonding involved, and there are no large attractive forces between the two gases.

Question 8

An unsaturated solution is one that __________.
A)has no double bonds
B)contains the maximum concentration of solute possible, and is in equilibrium with undissolved solute
C)has a concentration lower than the solubility
D)contains more dissolved solute than the solubility allows
E)contains no solute

Accepted Answer

An unsaturated solution is one that has a concentration lower than the solubility. It means that more solute can dissolve in the solution.

Question 9

A solution with a concentration higher than the solubility is __________.
A)is not possible
B)is unsaturated
C)is supercritical
D)is saturated
E)is supersaturated

Accepted Answer

A solution with a concentration higher than the solubility is considered supersaturated. This can occur when a solute is dissolved in a solvent at a higher temperature and then cooled down slowly, allowing more solute to dissolve than would normally be possible at the lower temperature.

Question 10

Which one of the following substances would be the most soluble in CCl₄? A)CH₃CH₂OH B)H₂O C)NH₃ D)C₁₀H₂₂ E)NaCl

Accepted Answer

CCl4 is a nonpolar solvent, and nonpolar substances are more soluble in nonpolar solvents. C10H22 (decane) is a nonpolar hydrocarbon, making it the most soluble in CCl4.

Question 11

Which one of the following vitamins is water soluble?
A)A
B)B
C)K
D)D
E)E

Accepted Answer

Vitamin B is water soluble, meaning it dissolves in water and is not stored in the body. Vitamins A, D, E, and K are fat soluble and can be stored in the body.

Question 12

When solutions of strong electrolytes in water are formed, the ions are surrounded by water molecules. These interactions are described as a case of __________.
A)hydration
B)supersaturation
C)crystallization
D)dehydration
E)saturation

Accepted Answer

The interaction between ions and water molecules is known as hydration.

Question 13

The dissolution of water in octane (C₈H₁₈)is prevented by __________. A)London dispersion forces between octane molecules B)hydrogen bonding between water molecules C)dipole-dipole attraction between octane molecules D)ion-dipole attraction between water and octane molecules E)repulsion between like-charged water and octane molecules

Accepted Answer

The answer of The dissolution of water in octane (C₈H₁₈)is...

Question 14

In a saturated solution of a salt in water, __________.
A)the rate of crystallization > the rate of dissolution
B)the rate of dissolution > the rate of crystallization
C)seed crystal addition may cause massive crystallization
D)the rate of crystallization = the rate of dissolution
E)addition of more water causes massive crystallization

Accepted Answer

In a saturated solution, the rate of crystallization is equal to the rate of dissolution, meaning that as fast as the solid is dissolving, the same amount is being deposited back on the solid surface. This creates an equilibrium condition where the concentration of the salt in solution stays constant, and no further net change occurs.

Question 15

The dissolution of gases in water is virtually always exothermic because __________.
A)one of the two endothermic steps (separation of solute particles)in the solution-formation process is unnecessary
B)the exothermic step in the solution-formation process is unnecessary
C)gases react exothermically with water
D)neither of the two endothermic steps in the solution-formation process is necessary
E)all three steps in the solution-formation process are exothermic

Accepted Answer

The dissolution of gases in water is exothermic because the step of separating solute particles (gas molecules) is not needed, as gases are already separated, reducing the energy required for dissolution.

Question 16

The phrase "like dissolves like" refers to the fact that __________.
A)gases can only dissolve other gases
B)polar solvents dissolve polar solutes and nonpolar solvents dissolve nonpolar solutes
C)solvents can only dissolve solutes of similar molar mass
D)condensed phases can only dissolve other condensed phases
E)polar solvents dissolve nonpolar solutes and vice versa

Accepted Answer

"Like dissolves like" means that solvents with similar polarities will dissolve solutes with similar polarities. Polar solvents, such as water, will dissolve polar solutes, such as salts and sugars, while nonpolar solvents, such as oil, will dissolve nonpolar solutes, such as fats and waxes. Therefore, option B is the correct answer.

Question 17

A supersaturated solution __________.
A)is one with more than one solute
B)is one that has been heated
C)is one with a higher concentration than the solubility
D)must be in contact with undissolved solid
E)exists only in theory and cannot actually be prepared

Accepted Answer

A supersaturated solution is a solution that contains more solute than the maximum amount that can be dissolved in the solvent at a given temperature. Therefore, a supersaturated solution has a higher concentration than the solubility. It must be in contact with undissolved solid to remain stable, but it doesn't necessarily need more than one solute or to be heated to become supersaturated. The existence of supersaturated solutions has been demonstrated experimentally and they can be prepared under certain conditions.

Question 18

A saturated solution __________.
A)contains as much solvent as it can hold
B)contains no double bonds
C)contains dissolved solute in equilibrium with undissolved solute
D)will rapidly precipitate if a seed crystal is added
E)cannot be attained

Accepted Answer

A saturated solution contains dissolved solute in equilibrium with undissolved solute, meaning that the rate of dissolution of solute is equal to the rate of precipitation of solute. It does not mean that the solution has as much solvent as it can hold (choice A) or that it contains no double bonds (choice B). Although adding a seed crystal may induce precipitation (choice D), it will not occur rapidly because the solution is already in equilibrium. While it is true that some solutes may not be able to dissolve to saturation (choice E), many substances can form saturated solutions.

Question 19

Ammonium nitrate (NH₄NO₃)dissolves readily in water even though the dissolution is endothermic by 26.4 kJ/mol. The solution process is spontaneous because __________. A)the vapor pressure of the water decreases upon addition of the solute B)osmotic properties predict this behavior C)of the decrease in enthalpy upon addition of the solute D)of the increase in enthalpy upon dissolution of this strong electrolyte E)of the increase in disorder upon dissolution of this strong electrolyte

Accepted Answer

The increase in disorder upon dissolution of a substance is quantified by its entropy change (∆S), which is expected to be positive for spontaneous dissolution. In this case, ammonium nitrate is a strong electrolyte that dissociates into ions when dissolved in water, leading to a significant increase in the number of particles in the solution and hence an increase in entropy. The endothermic nature of the dissolution (positive ∆H) is offset by the positive ∆S, resulting in a negative Gibbs free energy (∆G) and a spontaneous process. Choices A, B, C, and D do not provide a valid explanation for the spontaneous dissolution of ammonium nitrate.

Question 20

Hydration is a specific example of the phenomenon known generally as __________.
A)salutation
B)disordering
C)solvation
D)condensation
E)dilution

Accepted Answer

Hydration is a process of solvation where water molecules surround and form bonds with solute particles. Solvation is a general term used to describe the process where a solute dissolves in a solvent, and the solvent molecules surround the solute particles. Therefore, the best choice to complete the statement is C - solvation.

Quiz 13: Properties of Solutions

Which one of the following substances would be the least soluble in CCl₄?

Which of the following substances is more likely to dissolve in water?

The principal reason for the extremely low solubility of NaCl in benzene (C₆H₆) is the __________.

When two nonpolar organic liquids are mixed, a solution forms and the enthalpy of solution is quite small. Label the two organic liquids as A (solvent) and B (solute) . The formation of solution is favored by __________.

Compounds composed of a salt and water combined in definite proportions are known as

Formation of solutions where the process is endothermic can be spontaneous provided that __________.

When argon is placed in a container of neon, the argon spontaneously disperses throughout the neon because __________.

An unsaturated solution is one that __________.

A solution with a concentration higher than the solubility is __________.

Which one of the following substances would be the most soluble in CCl₄?

Which one of the following vitamins is water soluble?

When solutions of strong electrolytes in water are formed, the ions are surrounded by water molecules. These interactions are described as a case of __________.

The dissolution of water in octane (C₈H₁₈) is prevented by __________.

In a saturated solution of a salt in water, __________.

The dissolution of gases in water is virtually always exothermic because __________.

The phrase "like dissolves like" refers to the fact that __________.

A supersaturated solution __________.

A saturated solution __________.

Ammonium nitrate (NH₄NO₃) dissolves readily in water even though the dissolution is endothermic by 26.4 kJ/mol. The solution process is spontaneous because __________.

Hydration is a specific example of the phenomenon known generally as __________.