Question 1

Which statement about hydrogen bonding is true? A)Hydrogen bonding is the intermolecular attractive forces between two hydrogen atoms in solution. B)The hydrogen bonding capabilities of water molecules cause CH₃CH₂CH₂CH₃ to be more soluble in water than CH₃OH. C)Hydrogen bonding of solvent molecules with a solute will not affect the solubility of the solute. D)Hydrogen bonding interactions between molecules are stronger than the covalent bonds within the molecule. E)Hydrogen bonding arises from the dipole moment created by the unequal sharing of electrons within certain covalent bonds within a molecule.

Accepted Answer

Hydrogen bonding arises due to the dipole-dipole attraction between a hydrogen atom, which is covalently bonded to a highly electronegative atom (like oxygen, nitrogen, or fluorine), and another electronegative atom in a different molecule or within the same molecule if the geometry allows. This interaction is due to the dipole moment created by the unequal sharing of electrons in the covalent bond between hydrogen and the electronegative atom, making option E correct.

Question 2

We can predict the solubility of a compound by looking at the sign of the enthalpy of solution.

Accepted Answer

The solubility of a compound depends on both the enthalpy of solution and the entropy change associated with the dissolution process, not just the sign of the enthalpy of solution.

Question 3

The solubility of O₂ in water is 0.590 g/L at an oxygen pressure of around 14.5 atm.What is the Henry's law constant for O₂ (in units of mol/L·atm)? A)4.07 $\times$ 10^-² B)1.27 $\times$ 10^-³ C)7.86 $\times$ 10² D)2.67 $\times$ 10^-¹ E)None of the above are within 5% of the correct answer.

Accepted Answer

Henry's law constant (k) is given by the equation: k = C/P Where C is the solubility of the gas in the solvent and P is the partial pressure of the gas above the solvent. From the given data, C = 0.590 g/L P = 14.5 atm To convert the solubility from g/L to mol/L, we need to divide by the molar mass of O₂, which is 32 g/mol. So, C = 0.590 g/L ÷ 32 g/mol = 0.0184 mol/L Therefore, k = 0.0184 mol/L ÷ 14.5 atm = 1.27 × 10^−3 mol/L·atm This matches option B.

Question 4

What partial pressure of nitrogen gas is required in order for 0.00134 g of the gas to dissolve in 13.1 mL of pure water? The Henry's law constant for nitrogen gas is 6.1 $\times$ 10^-⁴ M atm^-¹. A)6.2 $\times$ 10^-⁸ atm B)1.7 $\times$ 10^-¹ atm C)6.0 $\times$ 10⁰ atm D)2.9 $\times$ 10^-⁸ atm E)1.7 $\times$ 10^-² atm

Accepted Answer

The answer of What partial pressure of nitrogen gas is...

Question 5

The vapor pressure of water at 25.0°C is 23.8 torr.Determine the mass of glucose (molar mass = 180 g/mol)needed to add to 500.0 g of water to change the vapor pressure to 22.8 torr.
A)21.9 g
B)219 g
C)180 g
D)6.21 kg
E)188 g

Accepted Answer

The answer of The vapor pressure of water at 25.0°C...

Question 6

What is the molarity of a HNO₃ solution prepared by adding 255.4 mL of water to 350.0 mL of 12.3 M HNO₃? A)16.9 M B)7.45 M C)7.11 M D)2.61 M E)3.14 M

Accepted Answer

Using the equation M1V1 = M2V2, where M1 and V1 are the initial concentration and volume, and M2 and V2 are the final concentration and volume, we can solve for the final concentration:

M1V1 = M2V2
(12.3 M)(350.0 mL) = M2(350.0 mL + 255.4 mL)
M2 = (12.3 M x 350.0 mL) / (350.0 mL + 255.4 mL)
M2 = 7.11 M

Therefore, the molarity of the final solution is 7.11 M.

Question 7

Solid KF has a lattice energy of 804 kJ/mol and a heat of solution (in water)of -15 kJ/mol.RbF has a lattice energy of 768 kJ/mol and a heat of solution (in water)of -24 kJ/mol.Which salt forms stronger attractions with water?
A)KF,since it has a larger lattice energy.
B)RbF,since it has a smaller lattice energy.
C)KF,since it has a more negative heat of hydration.
D)RbF,since it has a more negative heat of hydration
E)They form equally strong attractions with water,since they both have negative heats of mixing.

Accepted Answer

The heat of solution (hydration) is a measure of the strength of the attraction between an ion and a water molecule. A more negative heat of solution indicates a stronger attraction. Therefore, RbF has a stronger attraction with water since it has a more negative heat of solution (hydration) compared to KF. Even though KF has a larger lattice energy, it is not directly related to the attraction with water molecules.

Question 8

The lattice energy of KF is 808 kJ/mol and its heat of solution is -17.7 kJ/mol.Calculate the hydration of energy of KF(s).
A)-35.4 kJ/mol
B)-790.3 kJ/mol
C)-825.7 kJ/mol
D)790.3 kJ/mol
E)825.7 kJ/mol

Accepted Answer

The hydration energy of KF(s) can be calculated using the following equation:

ΔHsol = lattice energy + hydration energy

Where ΔHsol is the heat of solution.

Therefore,

Hydration energy = ΔHsol - lattice energy

Substituting the given values:

Hydration energy = -17.7 kJ/mol - 808 kJ/mol

Hydration energy = -825.7 kJ/mol

Hence, the correct answer is (C).

Question 9

Which of the following correctly states the relationship between temperature and the solubility of a substance in water?
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 rises,especially for ionic solids.
C)The solubility of a substance in water with temperature cannot be accurately predicted,especially for ionic solids.
D)The solubility of a substance in water decreases as the temperature lowers,especially for gases.
E)Both A and D are correct.

Accepted Answer

The answer of Which of the following correctly states the...

Question 10

Rank the following compounds according to increasing solubility in water. I. CH₃-CH₂-CH₂-CH₃ II. CH₃-CH₂-O-CH₂-CH₃ III. CH₃-CH₂-OH IV. CH₃-OH A)I < III < IV < II B)I < II < IV < III C)III < IV < II < I D)I < II < III < IV E)None of these (A-D)is correct.

Accepted Answer

The answer of Rank the following compounds according to increasing...

Question 11

When solid Ca(CH₃COO)₂ is dissolved in a nearly saturated solution of Ca(CH₃COO)₂,the solution becomes warmer.This information indicates that if the temperature of a solution is decreased: A)"$\Delta$H will become negative." B)"$\Delta$H will become zero." C)"The solubility of Ca(CH₃COO)₂ will decrease." D)"The solubility of Ca(CH₃COO)₂ will increase.' E)"The solubility of Ca(CH₃COO)₂ will not change."

Accepted Answer

The dissolution of Ca(CH3COO)2 in water is exothermic, as indicated by the solution becoming warmer. This implies that lowering the temperature will drive the equilibrium towards dissolving more solid to release heat, thus increasing the solubility of Ca(CH3COO)2.

Question 12

Calculate the molarity of a solution of magnesium chloride with a concentration of 26.8 mg/mL.
A)0.563 M
B)0.281 M
C)0.141 M
D)3.55 M
E)0.448 M

Accepted Answer

The answer of Calculate the molarity of a solution of...

Question 13

When 0.811 g of NH₄NO₃ was added to 150.0 g of water in a Styrofoam cup,the temperature dropped by 0.413°C.The heat capacity of H₂O is 4.18 J/g°C.Assume the specific heat of the solution equals that of pure H₂O and that the calorimeter neither absorbs nor leaks heat.The molar heat of solution of solid NH₄NO₃ is: A)+257 J/mol B)+25.7 kJ/mol C)+2.57 kJ/mol D)-2.57 kJ/mol E)-257 J/mol

Accepted Answer

The heat absorbed by the solution is calculated using q = mcΔT, where m is the mass of the solution (150.811 g), c is the specific heat capacity (4.18 J/g°C), and ΔT is the temperature change (0.413°C). The calculated q is then divided by the moles of NH₄NO₃ to find the molar heat of solution.

Question 14

When a substance dissolves in water,heat energy is released if:
A)The lattice energy is positive.
B)The hydration energy is positive.
C)The hydration energy is more negative than the lattice energy is positive.
D)The hydration energy is negative.
E)None of these (A-D).

Accepted Answer

When a substance dissolves in water and heat energy is released, it means the process is exothermic. This occurs when the hydration energy (energy released when ions are surrounded by water molecules) is more negative than the lattice energy (energy required to separate the ions in a solid) is positive. This means that more energy is released during hydration than is consumed to break the lattice, resulting in a net release of energy.

Question 15

Which of the following favors the solubility of an ionic solid in a liquid solvent?
A)a large magnitude of the solvation energy of the ions
B)a small magnitude of the lattice energy of the solute
C)a large polarity of the solvent
D)all of the above
E)none of the above

Accepted Answer

A large magnitude of the solvation energy of the ions favors the solubility of an ionic solid in a liquid solvent because it indicates that the solvent molecules can effectively surround the ions and stabilize them in solution. A small magnitude of the lattice energy of the solute also favors solubility because it suggests that the crystal lattice of the solid can easily be broken apart, releasing the ions into solution. A large polarity of the solvent also favors solubility because it allows for effective solvation of the charged ions. Therefore, all of the above factors favor solubility of an ionic solid in a liquid solvent.

Question 16

The solubility of a gas usually increases with increasing temperature.

Accepted Answer

The solubility of a gas in a liquid typically decreases as the temperature increases. This is because increasing temperature provides more energy to the gas molecules, making them less likely to dissolve in the liquid.

Question 17

Which of the following chemical or physical changes is an endothermic process?
A)the evaporation of water
B)the combustion of gasoline
C)the mixing of sulfuric acid and water
D)the freezing of water
E)none of these

Accepted Answer

The evaporation of water is an endothermic process because energy is absorbed in order to break the hydrogen bonds between water molecules and convert the liquid into a gas.

Question 18

A correct statement of Henry's law is:
A)The concentration of a gas in solution is inversely proportional to temperature.
B)The concentration of a gas in solution is directly proportional to the mole fraction of solvent.
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.

Accepted Answer

Henry's law states that the concentration of a gas in a solution is directly proportional to the partial pressure of that gas above the solution, which is not listed among the provided options.

Question 19

Use the following drawing of a gaseous solute in equilibrium with a solution to help answer the question below.  Which of the following statements are true when the piston is pushed in (downward)?
A)This will cause the pressure of the gas to increase and the concentration of the dissolved gas to go down.
B)This will cause the pressure of the gas to decrease and the concentration of the dissolved gas to go down.
C)This will cause the pressure of the gas to increase and the concentration of the dissolved gas to go up.
D)This will cause the volume of the gas to decrease and the concentration of the dissolved gas to go down.
E)This will cause the volume of the gas to increase and the concentration of the dissolved gas to go up.

Accepted Answer

The answer of Use the following drawing of a gaseous...

Question 20

How many of the following help determine whether or not a solution forms?
I.the polarities of the solute and solvent
II.the densities of the solute and solvent
III.the probability of the mixed state (of the solution)
IV.the energies needed for the solution formation to occur
V.the state of matter of the solute (solid,liquid,gas)
A)1
B)2
C)3
D)4
E)5

Accepted Answer

The polarities of the solute and solvent (I), the probability of the mixed state (III), and the energies needed for the solution formation (IV) are key factors in determining whether a solution forms. The densities (II) and the state of matter (V) are not primary factors.

Quiz 11: Properties of Solutions

Which statement about hydrogen bonding is true?

We can predict the solubility of a compound by looking at the sign of the enthalpy of solution.

The solubility of O₂ in water is 0.590 g/L at an oxygen pressure of around 14.5 atm.What is the Henry's law constant for O₂ (in units of mol/L·atm) ?

What partial pressure of nitrogen gas is required in order for 0.00134 g of the gas to dissolve in 13.1 mL of pure water? The Henry's law constant for nitrogen gas is 6.1 $\times$ 10^-⁴ M atm^-¹.

The vapor pressure of water at 25.0°C is 23.8 torr.Determine the mass of glucose (molar mass = 180 g/mol) needed to add to 500.0 g of water to change the vapor pressure to 22.8 torr.

What is the molarity of a HNO₃ solution prepared by adding 255.4 mL of water to 350.0 mL of 12.3 M HNO₃?

Solid KF has a lattice energy of 804 kJ/mol and a heat of solution (in water) of -15 kJ/mol.RbF has a lattice energy of 768 kJ/mol and a heat of solution (in water) of -24 kJ/mol.Which salt forms stronger attractions with water?

The lattice energy of KF is 808 kJ/mol and its heat of solution is -17.7 kJ/mol.Calculate the hydration of energy of KF(s) .

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

Rank the following compounds according to increasing solubility in water. I. CH₃-CH₂-CH₂-CH₃ II. CH₃-CH₂-O-CH₂-CH₃ III. CH₃-CH₂-OH IV. CH₃-OH

When solid Ca(CH₃COO) ₂ is dissolved in a nearly saturated solution of Ca(CH₃COO) ₂,the solution becomes warmer.This information indicates that if the temperature of a solution is decreased:

Calculate the molarity of a solution of magnesium chloride with a concentration of 26.8 mg/mL.

When a substance dissolves in water,heat energy is released if:

Which of the following favors the solubility of an ionic solid in a liquid solvent?

The solubility of a gas usually increases with increasing temperature.

Which of the following chemical or physical changes is an endothermic process?

A correct statement of Henry's law is:

Use the following drawing of a gaseous solute in equilibrium with a solution to help answer the question below. Which of the following statements are true when the piston is pushed in (downward) ?

Quiz 11: Properties of Solutions

Which statement about hydrogen bonding is true?

We can predict the solubility of a compound by looking at the sign of the enthalpy of solution.

The solubility of O2 in water is 0.590 g/L at an oxygen pressure of around 14.5 atm.What is the Henry's law constant for O2 (in units of mol/L·atm) ?

What partial pressure of nitrogen gas is required in order for 0.00134 g of the gas to dissolve in 13.1 mL of pure water? The Henry's law constant for nitrogen gas is 6.1 ×\times× 10-4 M atm-1.

The vapor pressure of water at 25.0°C is 23.8 torr.Determine the mass of glucose (molar mass = 180 g/mol) needed to add to 500.0 g of water to change the vapor pressure to 22.8 torr.

What is the molarity of a HNO3 solution prepared by adding 255.4 mL of water to 350.0 mL of 12.3 M HNO3?

Solid KF has a lattice energy of 804 kJ/mol and a heat of solution (in water) of -15 kJ/mol.RbF has a lattice energy of 768 kJ/mol and a heat of solution (in water) of -24 kJ/mol.Which salt forms stronger attractions with water?

The lattice energy of KF is 808 kJ/mol and its heat of solution is -17.7 kJ/mol.Calculate the hydration of energy of KF(s) .

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

Rank the following compounds according to increasing solubility in water. I. CH3-CH2-CH2-CH3 II. CH3-CH2-O-CH2-CH3 III. CH3-CH2-OH IV. CH3-OH

When solid Ca(CH3COO) 2 is dissolved in a nearly saturated solution of Ca(CH3COO) 2,the solution becomes warmer.This information indicates that if the temperature of a solution is decreased:

Calculate the molarity of a solution of magnesium chloride with a concentration of 26.8 mg/mL.

When a substance dissolves in water,heat energy is released if:

Which of the following favors the solubility of an ionic solid in a liquid solvent?

The solubility of a gas usually increases with increasing temperature.

Which of the following chemical or physical changes is an endothermic process?

A correct statement of Henry's law is:

Use the following drawing of a gaseous solute in equilibrium with a solution to help answer the question below. Which of the following statements are true when the piston is pushed in (downward) ?

The solubility of O₂ in water is 0.590 g/L at an oxygen pressure of around 14.5 atm.What is the Henry's law constant for O₂ (in units of mol/L·atm) ?

What partial pressure of nitrogen gas is required in order for 0.00134 g of the gas to dissolve in 13.1 mL of pure water? The Henry's law constant for nitrogen gas is 6.1 $\times$ 10^-⁴ M atm^-¹.

What is the molarity of a HNO₃ solution prepared by adding 255.4 mL of water to 350.0 mL of 12.3 M HNO₃?

Rank the following compounds according to increasing solubility in water. I. CH₃-CH₂-CH₂-CH₃ II. CH₃-CH₂-O-CH₂-CH₃ III. CH₃-CH₂-OH IV. CH₃-OH

When solid Ca(CH₃COO) ₂ is dissolved in a nearly saturated solution of Ca(CH₃COO) ₂,the solution becomes warmer.This information indicates that if the temperature of a solution is decreased: