Question 1

A solution is prepared by dissolving 40.0 g of sucrose, C₁₂H₂₂O₁₁, in 250. g of water at 25 °C. What is the vapour pressure of the solution if the vapour pressure of water at 25 °C is 23.76 mmHg? A) 0. 198 mmHg B) 20.5 mmHg C) 23.6 mmHg D) 24. 0 mmHg

Accepted Answer

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Question 2

What is the freezing point of a solution of 7.15 g MgCl₂ in 100 g of water? K_f for water is A) -0. 140 °C B) -1.40 °C C) -2.80 °C D) -4.19 °C

Accepted Answer

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Question 3

What is the expected freezing point of a 0.50 mol kg^-1 solution of Li₂SO₄ in water? K_f for water is 1.86 °C m^-1. A) -0.93 °C B) -1.9 °C C) -2.8 °C D) -6.5 °C

Accepted Answer

First, we need to find the van't Hoff factor (i) of the solute, LiS1U1B12S1U1B0SOS1U1B14S1U1B0. 
LiS1U1B12S1U1B0SOS1U1B14S1U1B0 dissociates into 3 ions in water: Li+, SO42-, and two CH3SO3-. This gives i = 3.

Next, we can plug in the given information into the freezing point depression equation:
∆Tf = i * Kf * molality 
∆Tf = (3)(1.86 °C mS1U1P1-1)(0.50 mol/kg) 
∆Tf = 2.79 °C

Finally, we can calculate the expected freezing point by taking the negative of ∆Tf:
Freezing point = 0°C - 2.79°C = -2.79°C

Rounding this to one decimal place gives us an answer of -2.8°C, which is choice C.

Question 4

Calculate the freezing point of a solution containing 5.0 grams of KCl and 550.0 grams of water. The molal freezing point depression constant (  ) for water is 
A) -0.45 °C
B) +0.45 °C
C) -0.23 °C
D) +0.23 °C
E) 1.23 °C

Accepted Answer

The answer of Calculate the freezing point of a solution...

Question 5

Match the following. -0.020 mol kg^-1 NH₄Cl A)solution of ionic compound with highest freezing point. B)solution that is most strongly dependent upon pressure C)solution with ΔT_b = 0.026 °C D)highest boiling point E)largest van't Hoff factor

Accepted Answer

The answer of Match the following. -0.020 mol kg^-1 NH₄Cl A)solution of...

Question 6

What happens to a supersaturated solution of potassium acetate once it is cooled and a small crystal of solid potassium acetate is added?

Accepted Answer

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Question 7

Why isn't pentanol (CH₃CH₂CH₂CH₂CH₂OH) very soluble in water?

Accepted Answer

The answer of Why isn't pentanol (CH₃CH₂CH₂CH₂CH₂OH) very soluble in...

Question 8

A solution is prepared by adding 40.00 g of lactose (milk sugar) to 110.0 g of water at  The partial pressure of water above the solution is ________ Torr. The vapour pressure of pure water at 55 °C is 0.1553 bar. The MW of lactose is 
A) 118.7
B) 8.268
C) 19.08
D) 2.188
E) 114.3

Accepted Answer

The answer of A solution is prepared by adding 40.00...

Question 9

Calculate the freezing point of a solution of 40.0 g salicylaldehyde, C₇H₆O₂, dissolved in 800. g of benzene, C₆H₆. and the freezing point is 5.50 °C for benzene. A) -2.09 °C B) 2.09 °C C) 3.41 °C D) 7.59 °C

Accepted Answer

The answer of Calculate the freezing point of a solution...

Question 10

A solution is prepared by dissolving 21.0 g of glycerin ( ) in 201 g of ethanol The freezing point of the solution is ________°C. The freezing point of pure ethanol is . The molal freezing point depression constant ( ) for ethanol is The molar masses of glycerin and of ethanol are 92.1 g mol^-1 and 46.1 g mol^-¹, respectively. A) -112.8 B) -116.4 C) 2.26 D) -112.3 E) -116.9

Accepted Answer

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Question 11

Explain why water does not dissolve in gasoline.

Accepted Answer

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Question 12

At 20 °C, a 0.389 mol L^-1 aqueous solution of ammonium chloride has a density of 1.0064 What is the mass % of ammonium chloride in the solution? The formula weight of Cl is A) 0.732% B) 2.59% C) 0.395% D) 0.387% E) 2.07%

Accepted Answer

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Question 13

At a given temperature the vapour pressures of benzene and toluene are 183 mmHg and 59.2 mmHg, respectively. Calculate the total vapour pressure over a solution of benzene and toluene with X_benzene = 0. 580. A) 106 mmHg B) 121 mmHg C) 131 mmHg D) 242 mmHg

Accepted Answer

Total vapour pressure over the solution can be calculated using Raoult's law: Total vapour pressure = Pbenzene + Ptoulene where Pbenzene is the vapour pressure of pure benzene and Ptoulene is the vapour pressure of pure toluene. According to Raoult's law, the vapour pressure of a component in the solution is equal to the product of its mole fraction and the vapour pressure of the pure component. Therefore, we can write: Pbenzene = X_benzene × P°benzene Ptoulene = (1 - X_benzene) × P°toluene where P°benzene and P°toluene are the vapour pressures of pure benzene and toluene, respectively. Substituting the values given in the question, we get: Pbenzene = 0.580 × 183 mmHg = 106.14 mmHg Ptoulene = (1 - 0.580) × 59.2 mmHg = 24.86 mmHg Therefore, the total vapour pressure over the solution is: Total vapour pressure = Pbenzene + Ptoulene = 106.14 mmHg + 24.86 mmHg = 131 mmHg Hence, the correct answer is C.

Question 14

Match the following. -0.050 mol kg^-1 C₆H₁₂O₆(aqueous) A)solution of ionic compound with highest freezing point. B)solution that is most strongly dependent upon pressure C)solution with ΔT_b = 0.026 °C D)highest boiling point E)largest van't Hoff factor

Accepted Answer

The boiling point elevation (ΔTb) is calculated using the formula ΔTb = i * Kb * m. For glucose (C6H12O6), which is a non-electrolyte, the van't Hoff factor (i) is 1. Given the molality (m) and the boiling point elevation constant (Kb), the solution with ΔTb = 0.026 °C matches the given concentration.

Question 15

An aqueous solution has a normal boiling point of 10 3.0 °C. What is the freezing point of this solution? For water  and 
A) -0. 82 °C
B) -3.0 °C
C) -3.6 °C
D) -11 °C

Accepted Answer

The answer of An aqueous solution has a normal boiling...

Question 16

Match the following. -0.050 mol kg^-1 NaCl A)solution of ionic compound with highest freezing point. B)solution that is most strongly dependent upon pressure C)solution with ΔT_b = 0.026 °C D)highest boiling point E)largest van't Hoff factor

Accepted Answer

The solution with the highest boiling point would have the highest concentration of solute particles, indicating a larger molality. Therefore, solution 0.050 mol kg^-1 NaCl would have the highest boiling point.

Question 17

Match the following. -0.010 mol kg^-1 Al(NO₃)₃ A)solution of ionic compound with highest freezing point. B)solution that is most strongly dependent upon pressure C)solution with ΔT_b = 0.026 °C D)highest boiling point E)largest van't Hoff factor

Accepted Answer

Al(NO3)3 dissociates into 4 ions (1 Al^3+ and 3 NO3^-), giving it the largest van't Hoff factor (i = 4) among typical ionic compounds.

Question 18

Match the following. -0.0050 mol kg^-1 CO₂ A)solution of ionic compound with highest freezing point. B)solution that is most strongly dependent upon pressure C)solution with ΔT_b = 0.026 °C D)highest boiling point E)largest van't Hoff factor

Accepted Answer

The solution of CO2 is most strongly dependent upon pressure because CO2 is a gas, and the solubility of gases in liquids is significantly affected by pressure changes according to Henry's Law.

Question 19

Which of the following solutions will have the lowest freezing point? A) 0.010 mol kg^-1 KBr B) 0.010 mol kg^-1 Na₂CO₃ C) 0.035 mol kg^-1 CH₃CH₂OH D) 0.015 mol kg^-1 BaCl₂

Accepted Answer

The solution with the lowest freezing point is the one with the highest molality and the greatest number of particles produced when dissolved. BaCl2 dissociates into 3 ions (1 Ba2+ and 2 Cl-), and with a molality of 0.015 mol/kg, it will produce more particles in solution compared to the other options, thus lowering the freezing point the most.

Question 20

A KCl solution is prepared by dissolving 25.0 g KCl in 250.0 g of water at 25 °C. What is the vapour pressure of the solution if the vapour pressure of water at 25 °C is 23.76 mmHg?
A) 21.6 mmHg
B) 22.7 mmHg
C) 23.2 mmHg
D) 24.9 mmHg

Accepted Answer

First, we need to calculate the mole fraction of KCl in the solution:

Mole fraction of KCl = moles of KCl / total moles of solution

The moles of KCl can be calculated as:

moles of KCl = mass of KCl / molar mass of KCl
moles of KCl = 25.0 g / 74.55 g/mol
moles of KCl = 0.335 mol

The total moles of the solution can be calculated as:

total moles of solution = moles of KCl + moles of water
total moles of solution = 0.335 mol + (250.0 g / 18.02 g/mol)
total moles of solution = 13.87 mol

Therefore, the mole fraction of KCl is:

Mole fraction of KCl = 0.335 mol / 13.87 mol
Mole fraction of KCl = 0.0241

Now we can use Raoult's law to calculate the vapour pressure of the solution:

vapour pressure of solution = mole fraction of solvent x vapour pressure of pure solvent

The mole fraction of solvent (water) can be calculated as:

mole fraction of water = moles of water / total moles of solution
mole fraction of water = (250.0 g / 18.02 g/mol) / 13.87 mol
mole fraction of water = 0.9759

The vapour pressure of the solution is therefore:

vapour pressure of solution = 0.9759 x 23.76 mmHg
vapour pressure of solution = 23.18 mmHg

Therefore, the best choice is B, with a calculated vapour pressure of 22.7 mmHg.

Quiz 12: Solutions

A solution is prepared by dissolving 40.0 g of sucrose, C₁₂H₂₂O₁₁, in 250. g of water at 25 °C. What is the vapour pressure of the solution if the vapour pressure of water at 25 °C is 23.76 mmHg?

What is the freezing point of a solution of 7.15 g MgCl₂ in 100 g of water? K_f for water is

What is the expected freezing point of a 0.50 mol kg^-1 solution of Li₂SO₄ in water? K_f for water is 1.86 °C m^-1.

Calculate the freezing point of a solution containing 5.0 grams of KCl and 550.0 grams of water. The molal freezing point depression constant ( ) for water is

Match the following. -0.020 mol kg^-1 NH₄Cl

What happens to a supersaturated solution of potassium acetate once it is cooled and a small crystal of solid potassium acetate is added?

Why isn't pentanol (CH₃CH₂CH₂CH₂CH₂OH) very soluble in water?

A solution is prepared by adding 40.00 g of lactose (milk sugar) to 110.0 g of water at The partial pressure of water above the solution is ________ Torr. The vapour pressure of pure water at 55 °C is 0.1553 bar. The MW of lactose is

Calculate the freezing point of a solution of 40.0 g salicylaldehyde, C₇H₆O₂, dissolved in 800. g of benzene, C₆H₆. and the freezing point is 5.50 °C for benzene.

Explain why water does not dissolve in gasoline.

At 20 °C, a 0.389 mol L^-1 aqueous solution of ammonium chloride has a density of 1.0064 What is the mass % of ammonium chloride in the solution? The formula weight of Cl is

At a given temperature the vapour pressures of benzene and toluene are 183 mmHg and 59.2 mmHg, respectively. Calculate the total vapour pressure over a solution of benzene and toluene with X_benzene = 0. 580.

Match the following. -0.050 mol kg^-1 C₆H₁₂O₆(aqueous)

An aqueous solution has a normal boiling point of 10 3.0 °C. What is the freezing point of this solution? For water and

Match the following. -0.050 mol kg^-1 NaCl

Match the following. -0.010 mol kg^-1 Al(NO₃) ₃

Match the following. -0.0050 mol kg^-1 CO₂

Which of the following solutions will have the lowest freezing point?

A KCl solution is prepared by dissolving 25.0 g KCl in 250.0 g of water at 25 °C. What is the vapour pressure of the solution if the vapour pressure of water at 25 °C is 23.76 mmHg?

Quiz 12: Solutions

A solution is prepared by dissolving 40.0 g of sucrose, C12H22O11, in 250. g of water at 25 °C. What is the vapour pressure of the solution if the vapour pressure of water at 25 °C is 23.76 mmHg?

What is the freezing point of a solution of 7.15 g MgCl2 in 100 g of water? Kf for water is

What is the expected freezing point of a 0.50 mol kg-1 solution of Li2SO4 in water? Kf for water is 1.86 °C m-1.

Calculate the freezing point of a solution containing 5.0 grams of KCl and 550.0 grams of water. The molal freezing point depression constant ( ) for water is

Match the following. -0.020 mol kg-1 NH4Cl

What happens to a supersaturated solution of potassium acetate once it is cooled and a small crystal of solid potassium acetate is added?

Why isn't pentanol (CH3CH2CH2CH2CH2OH) very soluble in water?

A solution is prepared by adding 40.00 g of lactose (milk sugar) to 110.0 g of water at The partial pressure of water above the solution is ________ Torr. The vapour pressure of pure water at 55 °C is 0.1553 bar. The MW of lactose is

Calculate the freezing point of a solution of 40.0 g salicylaldehyde, C7H6O2, dissolved in 800. g of benzene, C6H6. and the freezing point is 5.50 °C for benzene.

Explain why water does not dissolve in gasoline.

At 20 °C, a 0.389 mol L-1 aqueous solution of ammonium chloride has a density of 1.0064 What is the mass % of ammonium chloride in the solution? The formula weight of Cl is

At a given temperature the vapour pressures of benzene and toluene are 183 mmHg and 59.2 mmHg, respectively. Calculate the total vapour pressure over a solution of benzene and toluene with Xbenzene = 0. 580.

Match the following. -0.050 mol kg-1 C6H12O6 (aqueous)

An aqueous solution has a normal boiling point of 10 3.0 °C. What is the freezing point of this solution? For water and

Match the following. -0.050 mol kg-1 NaCl

Match the following. -0.010 mol kg-1 Al(NO3) 3

Match the following. -0.0050 mol kg-1 CO2

Which of the following solutions will have the lowest freezing point?

A KCl solution is prepared by dissolving 25.0 g KCl in 250.0 g of water at 25 °C. What is the vapour pressure of the solution if the vapour pressure of water at 25 °C is 23.76 mmHg?

A solution is prepared by dissolving 40.0 g of sucrose, C₁₂H₂₂O₁₁, in 250. g of water at 25 °C. What is the vapour pressure of the solution if the vapour pressure of water at 25 °C is 23.76 mmHg?

What is the freezing point of a solution of 7.15 g MgCl₂ in 100 g of water? K_f for water is

What is the expected freezing point of a 0.50 mol kg^-1 solution of Li₂SO₄ in water? K_f for water is 1.86 °C m^-1.

Match the following. -0.020 mol kg^-1 NH₄Cl

Why isn't pentanol (CH₃CH₂CH₂CH₂CH₂OH) very soluble in water?

Calculate the freezing point of a solution of 40.0 g salicylaldehyde, C₇H₆O₂, dissolved in 800. g of benzene, C₆H₆. and the freezing point is 5.50 °C for benzene.

At 20 °C, a 0.389 mol L^-1 aqueous solution of ammonium chloride has a density of 1.0064 What is the mass % of ammonium chloride in the solution? The formula weight of Cl is

At a given temperature the vapour pressures of benzene and toluene are 183 mmHg and 59.2 mmHg, respectively. Calculate the total vapour pressure over a solution of benzene and toluene with X_benzene = 0. 580.

Match the following. -0.050 mol kg^-1 C₆H₁₂O₆(aqueous)

Match the following. -0.050 mol kg^-1 NaCl

Match the following. -0.010 mol kg^-1 Al(NO₃) ₃

Match the following. -0.0050 mol kg^-1 CO₂