Question 1

Which has the higher vapor pressure at a given temperature, pure water or salty seawater? Explain.

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Question 2

What information is provided by the van 't Hoff factor?

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Question 3

Seawater can be characterized by the following average values. What is the molal concentration of ions in seawater? Explain how you arrived at your answer.
density = 1.022 g/mL
total mass of ions = 35.17 g/kg
concentration of ions = 1.15 M

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The answer of Seawater can be characterized by the following...

Question 4

Use the following data to calculate the lattice energy of lithium chloride, LiCl. $$\begin{array} { l r } 
 { \text { Quantity } } & \text { Magnitude } ( \mathbf { k J } / \mathbf { m o l } ) \
\text { Ionization energy of } \mathrm{Li}(g) & 519 \
\text { Electron affinity of } \mathrm{Cl}(g) & -349 \
\text { Vaporization energy of } \mathrm{Li}(s) & 147 \
\text { Bond energy of } \mathrm{Cl}_{2}(g) & 240\
\text { Reaction enthalpy: } \mathrm{Li}(s)+\frac{1}{2} \mathrm{Cl}_{2}(g) \rightarrow \mathrm{LiCl}(s)&-409
\end{array}$$

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Question 5

What is the molarity of a sucrose (C₁₂H₂₂O₁₁) solution that produces an osmotic pressure of 2)65 atm at 25°C?

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Question 6

Eugenol is a nonelectrolyte that contributes to the flavor of spices such as clove, nutmeg, cinnamon, and basil. A 328 mg sample of eugenol was dissolved in 10.0 g of chloroform (K_b = 3.63°C/m), increasing the boiling point of the chloroform by 0.726°C. What is the molar Mass of eugenol?

Accepted Answer

Explanation:ΔTb = Kb * m0.726°C = 3.63°C/m * mm = 0.200 mMoles of eugenol = m = 0.200 molMass of eugenol = 328 mg = 0.328 gMolar mass of eugenol = mass/moles = 0.328 g/0.200 mol = 164 g/mol

Question 7

A physiological saline solution is 0.92% NaCl by mass. What is the osmotic pressure of such a solution at a body temperature of 37°C?

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Question 8

Which statement is not correct? Determination of molar mass of an unknown sample by an osmotic pressure measurement requires that ________

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Question 9

A 376 mg sample of a nonelectrolyte compound isolated from throat lozenges was dissolved in water to produce 10.0 mL of a solution at 25°C. The osmotic pressure of this solution was measured and found to be 4.89 atm. What is the molar mass of this compound?

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The answer of A 376 mg sample of a nonelectrolyte...

Question 10

You are working as an intern in a biochemistry lab. Your advisor just isolated an enzyme and asks you to determine its molar mass using osmosis. You dissolve 1.0 g of the enzyme in water to make 250 mL of solution. You measure the osmotic pressure and find it to be 3.5 torr at 298 K. You report that the molar mass is ________ g/mol.

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Question 11

Does the temperature of the vapors in a still head increase or decrease as a fractional distillation progresses? Explain.

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Question 12

Rank the following ionic compounds in order of increasing lattice energy (largest lattice energy is the most negative): MgF₂, MgCl₂, MgBr₂, and MgI₂.

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Question 13

Calculate the minimum pressure that must be applied to achieve reverse osmosis of 0.504 M NaCl at 22$\degree$C.

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Question 14

Define the terms enthalpy of solution, enthalpy of hydration, and lattice energy.

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Question 15

A bottle is half-filled with a mixture of 25% liquid heptane and 75% liquid octane (mole fractions) at 25°C. What is the mole ratio of heptane to octane in the space above the liquid compared to in the liquid? The vapor pressures are 31 torr for pure heptane and 11 torr for pure octane.

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Question 16

A 300 mg sample of caffeine was dissolved in 10.0 g of camphor (K_f = 39.7°C/m), decreasing the freezing point of camphor by 3.07°C. What is the molar mass of caffeine?

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Question 17

Use the following data to calculate the enthalpy change for the following reaction: $$\begin{array} { l c } 
 { 2 \mathrm { Na } ( \mathrm { s } ) + \frac { \mathrm { 1 } } { 2 } \mathrm { O } _ { 2 } ( g ) }  \rightarrow \mathrm { Na } _ { 2 } \mathrm { O } ( s ) \
\text { Quantity } & \text { Magnitude } ( \mathbf { k J } / \mathbf { m o l } ) \
\text { Ionization energy of } \mathrm { Na } ( g ) & 495 \
\text { Electron affinity of } \mathrm { O } ( g ) \text { for } 2 \mathrm { e } & 603 \
\text { Vaporization energy of } \mathrm { Na } ( s ) & 109 \
\text { Bond energy of } \mathrm { O } _ { 2 } ( g ) & 499 \
\text { Lattice energy for } \mathrm { Na } _ { 2 } \mathrm { O } ( s ) & - 2,477
\end{array}$$

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Question 18

Caryophyllene, a nonelectrolyte, is one of the compounds responsible for the flavor of cloves. A 207 mg sample of caryophyllene was dissolved in 1.00 g of chloroform (K_b = 3.63°C/m), increasing the boiling point of chloroform by 3.68°C. What is the molar mass of caryophyllene?

Accepted Answer

The boiling point elevation formula is ΔT = i * Kb * m. Since caryophyllene is a nonelectrolyte, i = 1. Rearranging the formula to find molality (m), we get m = ΔT / Kb = 3.68°C / 3.63°C/m = 1.0138 m. Molality is moles of solute per kg of solvent, so moles of caryophyllene = 1.0138 m * 0.001 kg = 0.0010138 mol. The molar mass is mass/moles = 0.207 g / 0.0010138 mol = 204 g/mol.

Question 19

A 15.0 mg sample of a protein was dissolved in water to produce 5.00 mL of solution at 25.1°C. The osmotic pressure of this solution was measured and found to be 6.50 torr. What is the molar mass of this protein?

Accepted Answer

We can use the formula for osmotic pressure:

π = MRT

where π is the osmotic pressure, M is the molarity, R is the gas constant (0.08206 L atm K^-1mol^-1), and T is the temperature in Kelvin.

We can rearrange the equation to solve for the molarity:

M = π/RT

We need to convert the mass of protein to moles:

moles = mass/molar mass

Since we want to find the molar mass, we can rearrange this equation:

molar mass = mass/moles

We are given the mass (15.0 mg) and the volume of solution (5.00 mL), which we can convert to L:

5.00 mL = 0.00500 L

We also know the temperature (25.1°C = 298.25 K) and the osmotic pressure (6.50 torr).

Now we can plug in these values and solve for the molar mass:

M = π/RT = (6.50 torr)/(0.08206 L atm K^-1mol^-1 x 298.25 K) = 0.00272 M

moles = mass/molar mass = (15.0 mg)/(0.00272 M) = 5.51 x 10^-6 mol

molar mass = mass/moles = (15.0 mg)/(5.51 x 10^-6 mol) = 2.72 x 10^6 g/mol

However, this is the molar mass of the protein in grams, not in the conventional units of g/mol. Converting to g/mol:

molar mass = 2.72 x 10^6 g/mol / 1000 g/kg = 2.72 x 10^3 kg/mol

Finally, we can convert to the conventional units of g/mol:

molar mass = 2.72 x 10^3 kg/mol x 1000 g/kg = 2.72 x 10^6 g/mol

Therefore, the molar mass of this protein is 8,580 g/mol.

Question 20

The term colligative refers to properties that ________

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Quiz 11: Solutions: Properties and Behavior

Which has the higher vapor pressure at a given temperature, pure water or salty seawater? Explain.

What information is provided by the van 't Hoff factor?

Seawater can be characterized by the following average values. What is the molal concentration of ions in seawater? Explain how you arrived at your answer. density = 1.022 g/mL total mass of ions = 35.17 g/kg concentration of ions = 1.15 M

What is the molarity of a sucrose (C₁₂H₂₂O₁₁) solution that produces an osmotic pressure of 2) 65 atm at 25°C?

Eugenol is a nonelectrolyte that contributes to the flavor of spices such as clove, nutmeg, cinnamon, and basil. A 328 mg sample of eugenol was dissolved in 10.0 g of chloroform (K_b = 3.63°C/m) , increasing the boiling point of the chloroform by 0.726°C. What is the molar Mass of eugenol?

A physiological saline solution is 0.92% NaCl by mass. What is the osmotic pressure of such a solution at a body temperature of 37°C?

Which statement is not correct? Determination of molar mass of an unknown sample by an osmotic pressure measurement requires that ________

A 376 mg sample of a nonelectrolyte compound isolated from throat lozenges was dissolved in water to produce 10.0 mL of a solution at 25°C. The osmotic pressure of this solution was measured and found to be 4.89 atm. What is the molar mass of this compound?

Does the temperature of the vapors in a still head increase or decrease as a fractional distillation progresses? Explain.

Rank the following ionic compounds in order of increasing lattice energy (largest lattice energy is the most negative): MgF₂, MgCl₂, MgBr₂, and MgI₂.

Calculate the minimum pressure that must be applied to achieve reverse osmosis of 0.504 M NaCl at 22 $\degree$ C.

Define the terms enthalpy of solution, enthalpy of hydration, and lattice energy.

A bottle is half-filled with a mixture of 25% liquid heptane and 75% liquid octane (mole fractions) at 25°C. What is the mole ratio of heptane to octane in the space above the liquid compared to in the liquid? The vapor pressures are 31 torr for pure heptane and 11 torr for pure octane.

A 300 mg sample of caffeine was dissolved in 10.0 g of camphor (K_f = 39.7°C/m) , decreasing the freezing point of camphor by 3.07°C. What is the molar mass of caffeine?

Caryophyllene, a nonelectrolyte, is one of the compounds responsible for the flavor of cloves. A 207 mg sample of caryophyllene was dissolved in 1.00 g of chloroform (K_b = 3.63°C/m) , increasing the boiling point of chloroform by 3.68°C. What is the molar mass of caryophyllene?

A 15.0 mg sample of a protein was dissolved in water to produce 5.00 mL of solution at 25.1°C. The osmotic pressure of this solution was measured and found to be 6.50 torr. What is the molar mass of this protein?

The term colligative refers to properties that ________

Quiz 11: Solutions: Properties and Behavior

Which has the higher vapor pressure at a given temperature, pure water or salty seawater? Explain.

What information is provided by the van 't Hoff factor?

Seawater can be characterized by the following average values. What is the molal concentration of ions in seawater? Explain how you arrived at your answer. density = 1.022 g/mL total mass of ions = 35.17 g/kg concentration of ions = 1.15 M

What is the molarity of a sucrose (C12H22O11) solution that produces an osmotic pressure of 2) 65 atm at 25°C?

Eugenol is a nonelectrolyte that contributes to the flavor of spices such as clove, nutmeg, cinnamon, and basil. A 328 mg sample of eugenol was dissolved in 10.0 g of chloroform (Kb = 3.63°C/m) , increasing the boiling point of the chloroform by 0.726°C. What is the molar Mass of eugenol?

A physiological saline solution is 0.92% NaCl by mass. What is the osmotic pressure of such a solution at a body temperature of 37°C?

Which statement is not correct? Determination of molar mass of an unknown sample by an osmotic pressure measurement requires that ________

A 376 mg sample of a nonelectrolyte compound isolated from throat lozenges was dissolved in water to produce 10.0 mL of a solution at 25°C. The osmotic pressure of this solution was measured and found to be 4.89 atm. What is the molar mass of this compound?

Does the temperature of the vapors in a still head increase or decrease as a fractional distillation progresses? Explain.

Rank the following ionic compounds in order of increasing lattice energy (largest lattice energy is the most negative): MgF2, MgCl2, MgBr2, and MgI2.

Calculate the minimum pressure that must be applied to achieve reverse osmosis of 0.504 M NaCl at 22 °\degree° C.

Define the terms enthalpy of solution, enthalpy of hydration, and lattice energy.

A bottle is half-filled with a mixture of 25% liquid heptane and 75% liquid octane (mole fractions) at 25°C. What is the mole ratio of heptane to octane in the space above the liquid compared to in the liquid? The vapor pressures are 31 torr for pure heptane and 11 torr for pure octane.

A 300 mg sample of caffeine was dissolved in 10.0 g of camphor (Kf = 39.7°C/m) , decreasing the freezing point of camphor by 3.07°C. What is the molar mass of caffeine?

Caryophyllene, a nonelectrolyte, is one of the compounds responsible for the flavor of cloves. A 207 mg sample of caryophyllene was dissolved in 1.00 g of chloroform (Kb = 3.63°C/m) , increasing the boiling point of chloroform by 3.68°C. What is the molar mass of caryophyllene?

A 15.0 mg sample of a protein was dissolved in water to produce 5.00 mL of solution at 25.1°C. The osmotic pressure of this solution was measured and found to be 6.50 torr. What is the molar mass of this protein?

The term colligative refers to properties that ________

What is the molarity of a sucrose (C₁₂H₂₂O₁₁) solution that produces an osmotic pressure of 2) 65 atm at 25°C?

Eugenol is a nonelectrolyte that contributes to the flavor of spices such as clove, nutmeg, cinnamon, and basil. A 328 mg sample of eugenol was dissolved in 10.0 g of chloroform (K_b = 3.63°C/m) , increasing the boiling point of the chloroform by 0.726°C. What is the molar Mass of eugenol?

Rank the following ionic compounds in order of increasing lattice energy (largest lattice energy is the most negative): MgF₂, MgCl₂, MgBr₂, and MgI₂.

Calculate the minimum pressure that must be applied to achieve reverse osmosis of 0.504 M NaCl at 22 $\degree$ C.

A 300 mg sample of caffeine was dissolved in 10.0 g of camphor (K_f = 39.7°C/m) , decreasing the freezing point of camphor by 3.07°C. What is the molar mass of caffeine?

Caryophyllene, a nonelectrolyte, is one of the compounds responsible for the flavor of cloves. A 207 mg sample of caryophyllene was dissolved in 1.00 g of chloroform (K_b = 3.63°C/m) , increasing the boiling point of chloroform by 3.68°C. What is the molar mass of caryophyllene?