Question 1

For a dilute aqueous solution, a concentration of 1 ppm also corresponds to a concentration of 1 __________ per liter of solution.

Accepted Answer

The answer of For a dilute aqueous solution, a concentration...

Question 2

A solution is prepared by dissolving 14.0 g of NH₃ in 250.0 g of water. The density of the resulting solution is 0.974 g/mL. The mole fraction of NH₃ in the solution is __________.

Accepted Answer

To find the mole fraction of NH3, calculate the moles of NH3 and water, then divide the moles of NH3 by the total moles. Moles of NH3 = 14.0 g / 17.03 g/mol = 0.822 moles. Moles of water = 250.0 g / 18.02 g/mol = 13.88 moles. Mole fraction of NH3 = 0.822 / (0.822 + 13.88) = 0.0560.

Question 3

A solution is prepared by adding 30.00 g of lactose (milk sugar)to 110.0 g of water at 55°C. The partial pressure of water above the solution is __________ torr. The vapor pressure of pure water at 55°C is 118.0 torr. The MW of lactose is 342.3 g/mol.

Accepted Answer

The partial pressure of water above the solution can be calculated using Raoult's Law: P_solution = X_solvent * P_pure. First, calculate the mole fraction of water (solvent). Moles of lactose = 30.00 g / 342.3 g/mol = 0.0877 mol. Moles of water = 110.0 g / 18.015 g/mol = 6.107 mol. Mole fraction of water = 6.107 / (6.107 + 0.0877) = 0.986. P_solution = 0.986 * 118.0 torr = 116.3 torr.

Question 4

The concentration of a benzene solution prepared by mixing 11.0 g C₆H₆ with 38.0 g CCl₄ is __________ molal.

Accepted Answer

The answer of The concentration of a benzene solution prepared...

Question 5

A solution is prepared by dissolving 16.2 g of benzene (C₆H₆)in 282 g of carbon tetrachloride (CCl₄). The concentration of benzene in this solution is __________ molal. The molar masses of C₆H₆ and CCl₄ are 78.0 g/mol and 154 g/mol, respectively.

Accepted Answer

To find the molality, calculate the moles of benzene (16.2 g / 78.0 g/mol = 0.2077 mol) and the mass of carbon tetrachloride in kg (282 g = 0.282 kg). Molality = moles of solute / kg of solvent = 0.2077 mol / 0.282 kg = 0.736 mol/kg.

Question 6

The vapor pressure of pure water at 25°C is 23.8 torr. Determine the vapor pressure (torr)of water at 25°C above a solution prepared by dissolving 21 g of urea (a nonvolatile, non-electrolyte, MW = 60.0g/mol)in 75 g of water.

Accepted Answer

The vapor pressure of the solution can be found using Raoult's Law: P_solution = X_solvent * P_pure solvent. First, calculate the moles of urea (21 g / 60 g/mol = 0.35 mol) and water (75 g / 18 g/mol = 4.17 mol). The mole fraction of water is 4.17 / (4.17 + 0.35) = 0.923. Thus, the vapor pressure of the solution is 0.923 * 23.8 torr = 22 torr.

Question 7

A solution is prepared by adding 1.43 mol of KCl to 889 g of water. The concentration of KCl is __________ molal.

Accepted Answer

The answer of A solution is prepared by adding 1.43...

Question 8

At 20°C, a 0.376 M aqueous solution of ammonium chloride has a density of 1.0045 g/mL. What is the mass % of ammonium chloride in the solution? The formula weight of NH₄Cl is 53.50 g/mol.

Accepted Answer

The answer of At 20°C, a 0.376 M aqueous solution...

Question 9

The concentration of sodium chloride in an aqueous solution that is 2.23 M and that has a density of 1.01 g/mL is __________% by mass.

Accepted Answer

The answer of The concentration of sodium chloride in an...

Question 10

At 20°C, a 2.32 M aqueous solution of ammonium chloride has a density of 1.0344 g/mL. What is the molality of ammonium chloride in the solution? The formula weight of NH₄Cl is 53.50 g/mol.

Accepted Answer

To find molality, we need moles of solute per kg of solvent. First, calculate the mass of the solution using its density (1.0344 g/mL) and volume (1 L for 2.32 moles). Then, subtract the mass of NH4Cl (2.32 moles * 53.50 g/mol) from the total mass to find the mass of the solvent. Finally, divide the moles of NH4Cl by the mass of the solvent in kg.

Question 11

A solution is prepared by dissolving 7.00 g of glycerin (C₃H₈O₃)in 201 g of ethanol (C₂H₅OH). The freezing point of the solution is __________°C. The freezing point of pure ethanol is -114.6°C at 1 atm. The molal-freezing-point-depression constant (K_f)for ethanol is 1.99°C/m. The molar masses of glycerin and of ethanol are 92.1 g/mol and 46.1 g/mol, respectively.

Accepted Answer

The answer of A solution is prepared by dissolving 7.00...

Question 12

Calculate the freezing point of a 0.08500 m aqueous solution of NaNO₃. The molal freezing-point-depression constant of water is 1.86°C/m.

Accepted Answer

The freezing point depression is calculated using the formula ΔTf = i * Kf * m, where i is the van't Hoff factor (2 for NaNO3), Kf is the freezing-point-depression constant (1.86°C/m), and m is the molality (0.08500 m). ΔTf = 2 * 1.86 * 0.08500 = 0.316°C. The freezing point of water is 0°C, so the new freezing point is 0 - 0.316 = -0.316°C.

Question 13

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 (K_f)for water is 1.86°C/m.

Accepted Answer

The freezing point depression is calculated using ΔTf = i * Kf * m, where i is the van't Hoff factor for KCl (which is 2), Kf is 1.86°C/m, and m is the molality of the solution. First, calculate the molality: moles of KCl = 5.0 g / 74.55 g/mol = 0.067 moles; molality = 0.067 moles / 0.550 kg = 0.122 m. Then, ΔTf = 2 * 1.86°C/m * 0.122 m = 0.45°C. The freezing point is lowered, so it's -0.45°C.

Question 14

Water (H₂O)and the alcohol methanol (CH₃OH)are infinitely soluble in each other. The primary intermolecular force responsible for this is __________.

Accepted Answer

The answer of Water (H₂O)and the alcohol methanol (CH₃OH)are infinitely...

Question 15

At 20°C, an aqueous solution that is 24.0% by mass in ammonium chloride has a density of 1.0674g/mL. What is the molarity of ammonium chloride in the solution? The formula weight of NH₄Cl is 53.50 g/mol.

Accepted Answer

To find the molarity of ammonium chloride in the solution, we need to first calculate the mass of ammonium chloride present in 1 liter of the solution.

Let's assume we have 100g of the solution, which means that we have 24g of ammonium chloride and 76g of water.

Using the density of the solution, we can calculate the volume of 100g of the solution:

density = mass/volume

1.0674 g/mL = 100g/volume

volume = 93.7 mL = 0.0937 L

Now, we can use the mass of ammonium chloride and its formula weight to calculate the number of moles present in the solution:

moles of NH4Cl = mass of NH4Cl / formula weight of NH4Cl

moles of NH4Cl = 24g / 53.50 g/mol

moles of NH4Cl = 0.449 mol

Finally, we can calculate the molarity of the solution:

Molarity = moles of solute / volume of solution in liters

Molarity = 0.449 mol / 0.0937 L

Molarity = 4.79 M

Therefore, the answer is C) 4.79.

Question 16

The freezing point of ethanol (C₂H₅OH)is -114.6°C. The molal freezing point depression constant for ethanol is 2.00°C/m. What is the freezing point (°C)of a solution prepared by dissolving 40.0 g of glycerin (C₃H₈O₃, a nonelectrolyte)in 200.0 g of ethanol?

Accepted Answer

First, calculate the molality of the solution:

moles of glycerin = mass/molar mass = 40.0 g/92.09 g/mol = 0.4344 mol
mass of solvent = 200.0 g ethanol
molality = moles of solute/kg of solvent = 0.4344 mol /0.200 kg = 2.17 mol/kg

Next, use the molal freezing point depression constant and molality to calculate the change in freezing point:

ΔTf = Kf × molality = (2.00°C/m)×(2.17 mol/kg) = 4.34°C

Finally, subtract the change in freezing point from the normal freezing point of ethanol to get the new freezing point:

freezing point = normal freezing point - ΔTf = (-114.6°C) - (4.34°C) = -118.9°C

Thus, the freezing point of the solution is -118.9°C.

Question 17

Calculate the freezing point of a 0.08500 m aqueous solution of glucose. The molal freezing-point-depression constant of water is 1.86°C/m.

Accepted Answer

The answer of Calculate the freezing point of a 0.08500...

Question 18

The mole fraction of He in a gaseous solution prepared from 3.0 g of He, 6.5 g of Ar, and 10.0 g of Ne is __________.

Accepted Answer

The mole fraction of a component in a gaseous solution is equal to the number of moles of that component divided by the total number of moles of all components in the solution. The molar mass of He is 4.00 g/mol, the molar mass of Ar is 39.95 g/mol, and the molar mass of Ne is 20.18 g/mol. Therefore, the number of moles of He in the solution is 3.0 g / 4.00 g/mol = 0.75 mol, the number of moles of Ar in the solution is 6.5 g / 39.95 g/mol = 0.163 mol, and the number of moles of Ne in the solution is 10.0 g / 20.18 g/mol = 0.496 mol. The total number of moles of all components in the solution is 0.75 mol + 0.163 mol + 0.496 mol = 1.41 mol. Therefore, the mole fraction of He in the solution is 0.75 mol / 1.41 mol = 0.53.

Question 19

The formula weight of FeCl₃^.6H₂O is __________.

Accepted Answer

The answer of The formula weight of FeCl₃^.6H₂O is __________....

Question 20

The osmotic pressure of a solution formed by dissolving 25.0 mg of aspirin (C₉H₈O₄)in 0.250 L of water at 25°C is __________ atm.

Accepted Answer

We can use the equation for calculating the osmotic pressure of a solution π = MRT, where M is the molar concentration of the solute, R is the gas constant, and T is the temperature in Kelvin.

First, we need to calculate the molar concentration of aspirin: 
Molar mass of aspirin = 180.16 g/mol 
Moles of aspirin = 25.0 mg / 180.16 g/mol = 0.000139 moles 
Molarity of aspirin = 0.000139 moles / 0.250 L = 0.000556 M

Next, we can plug in the values into the equation: 
π = (0.000556 M)(0.0821 L·atm/mol·K)(298 K) = 0.0136 atm

Therefore, the osmotic pressure of the solution is 0.0136 atm. The answer is (C).

Quiz 13: Properties of Solutions

For a dilute aqueous solution, a concentration of 1 ppm also corresponds to a concentration of 1 __________ per liter of solution.

A solution is prepared by dissolving 14.0 g of NH₃ in 250.0 g of water. The density of the resulting solution is 0.974 g/mL. The mole fraction of NH₃ in the solution is __________.

A solution is prepared by adding 30.00 g of lactose (milk sugar) to 110.0 g of water at 55°C. The partial pressure of water above the solution is __________ torr. The vapor pressure of pure water at 55°C is 118.0 torr. The MW of lactose is 342.3 g/mol.

The concentration of a benzene solution prepared by mixing 11.0 g C₆H₆ with 38.0 g CCl₄ is __________ molal.

A solution is prepared by dissolving 16.2 g of benzene (C₆H₆) in 282 g of carbon tetrachloride (CCl₄) . The concentration of benzene in this solution is __________ molal. The molar masses of C₆H₆ and CCl₄ are 78.0 g/mol and 154 g/mol, respectively.

The vapor pressure of pure water at 25°C is 23.8 torr. Determine the vapor pressure (torr) of water at 25°C above a solution prepared by dissolving 21 g of urea (a nonvolatile, non-electrolyte, MW = 60.0g/mol) in 75 g of water.

A solution is prepared by adding 1.43 mol of KCl to 889 g of water. The concentration of KCl is __________ molal.

At 20°C, a 0.376 M aqueous solution of ammonium chloride has a density of 1.0045 g/mL. What is the mass % of ammonium chloride in the solution? The formula weight of NH₄Cl is 53.50 g/mol.

The concentration of sodium chloride in an aqueous solution that is 2.23 M and that has a density of 1.01 g/mL is __________% by mass.

At 20°C, a 2.32 M aqueous solution of ammonium chloride has a density of 1.0344 g/mL. What is the molality of ammonium chloride in the solution? The formula weight of NH₄Cl is 53.50 g/mol.

Calculate the freezing point of a 0.08500 m aqueous solution of NaNO₃. The molal freezing-point-depression constant of water is 1.86°C/m.

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 (K_f) for water is 1.86°C/m.

Water (H₂O)and the alcohol methanol (CH₃OH)are infinitely soluble in each other. The primary intermolecular force responsible for this is __________.

At 20°C, an aqueous solution that is 24.0% by mass in ammonium chloride has a density of 1.0674g/mL. What is the molarity of ammonium chloride in the solution? The formula weight of NH₄Cl is 53.50 g/mol.

The freezing point of ethanol (C₂H₅OH) is -114.6°C. The molal freezing point depression constant for ethanol is 2.00°C/m. What is the freezing point (°C) of a solution prepared by dissolving 40.0 g of glycerin (C₃H₈O₃, a nonelectrolyte) in 200.0 g of ethanol?

Calculate the freezing point of a 0.08500 m aqueous solution of glucose. The molal freezing-point-depression constant of water is 1.86°C/m.

The mole fraction of He in a gaseous solution prepared from 3.0 g of He, 6.5 g of Ar, and 10.0 g of Ne is __________.

The formula weight of FeCl₃^.6H₂O is __________.

The osmotic pressure of a solution formed by dissolving 25.0 mg of aspirin (C₉H₈O₄) in 0.250 L of water at 25°C is __________ atm.

Quiz 13: Properties of Solutions

For a dilute aqueous solution, a concentration of 1 ppm also corresponds to a concentration of 1 __________ per liter of solution.

A solution is prepared by dissolving 14.0 g of NH3 in 250.0 g of water. The density of the resulting solution is 0.974 g/mL. The mole fraction of NH3 in the solution is __________.

A solution is prepared by adding 30.00 g of lactose (milk sugar) to 110.0 g of water at 55°C. The partial pressure of water above the solution is __________ torr. The vapor pressure of pure water at 55°C is 118.0 torr. The MW of lactose is 342.3 g/mol.

The concentration of a benzene solution prepared by mixing 11.0 g C6H6 with 38.0 g CCl4 is __________ molal.

A solution is prepared by dissolving 16.2 g of benzene (C6H6) in 282 g of carbon tetrachloride (CCl4) . The concentration of benzene in this solution is __________ molal. The molar masses of C6H6 and CCl4 are 78.0 g/mol and 154 g/mol, respectively.

The vapor pressure of pure water at 25°C is 23.8 torr. Determine the vapor pressure (torr) of water at 25°C above a solution prepared by dissolving 21 g of urea (a nonvolatile, non-electrolyte, MW = 60.0g/mol) in 75 g of water.

A solution is prepared by adding 1.43 mol of KCl to 889 g of water. The concentration of KCl is __________ molal.

At 20°C, a 0.376 M aqueous solution of ammonium chloride has a density of 1.0045 g/mL. What is the mass % of ammonium chloride in the solution? The formula weight of NH4Cl is 53.50 g/mol.

The concentration of sodium chloride in an aqueous solution that is 2.23 M and that has a density of 1.01 g/mL is __________% by mass.

At 20°C, a 2.32 M aqueous solution of ammonium chloride has a density of 1.0344 g/mL. What is the molality of ammonium chloride in the solution? The formula weight of NH4Cl is 53.50 g/mol.

Calculate the freezing point of a 0.08500 m aqueous solution of NaNO3. The molal freezing-point-depression constant of water is 1.86°C/m.

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 (Kf) for water is 1.86°C/m.

Water (H2O)and the alcohol methanol (CH3OH)are infinitely soluble in each other. The primary intermolecular force responsible for this is __________.

At 20°C, an aqueous solution that is 24.0% by mass in ammonium chloride has a density of 1.0674g/mL. What is the molarity of ammonium chloride in the solution? The formula weight of NH4Cl is 53.50 g/mol.

The freezing point of ethanol (C2H5OH) is -114.6°C. The molal freezing point depression constant for ethanol is 2.00°C/m. What is the freezing point (°C) of a solution prepared by dissolving 40.0 g of glycerin (C3H8O3, a nonelectrolyte) in 200.0 g of ethanol?

Calculate the freezing point of a 0.08500 m aqueous solution of glucose. The molal freezing-point-depression constant of water is 1.86°C/m.

The mole fraction of He in a gaseous solution prepared from 3.0 g of He, 6.5 g of Ar, and 10.0 g of Ne is __________.

The formula weight of FeCl3.6H2O is __________.

The osmotic pressure of a solution formed by dissolving 25.0 mg of aspirin (C9H8O4) in 0.250 L of water at 25°C is __________ atm.

A solution is prepared by dissolving 14.0 g of NH₃ in 250.0 g of water. The density of the resulting solution is 0.974 g/mL. The mole fraction of NH₃ in the solution is __________.

The concentration of a benzene solution prepared by mixing 11.0 g C₆H₆ with 38.0 g CCl₄ is __________ molal.

A solution is prepared by dissolving 16.2 g of benzene (C₆H₆) in 282 g of carbon tetrachloride (CCl₄) . The concentration of benzene in this solution is __________ molal. The molar masses of C₆H₆ and CCl₄ are 78.0 g/mol and 154 g/mol, respectively.

At 20°C, a 0.376 M aqueous solution of ammonium chloride has a density of 1.0045 g/mL. What is the mass % of ammonium chloride in the solution? The formula weight of NH₄Cl is 53.50 g/mol.

At 20°C, a 2.32 M aqueous solution of ammonium chloride has a density of 1.0344 g/mL. What is the molality of ammonium chloride in the solution? The formula weight of NH₄Cl is 53.50 g/mol.

Calculate the freezing point of a 0.08500 m aqueous solution of NaNO₃. The molal freezing-point-depression constant of water is 1.86°C/m.

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 (K_f) for water is 1.86°C/m.

Water (H₂O)and the alcohol methanol (CH₃OH)are infinitely soluble in each other. The primary intermolecular force responsible for this is __________.

At 20°C, an aqueous solution that is 24.0% by mass in ammonium chloride has a density of 1.0674g/mL. What is the molarity of ammonium chloride in the solution? The formula weight of NH₄Cl is 53.50 g/mol.

The freezing point of ethanol (C₂H₅OH) is -114.6°C. The molal freezing point depression constant for ethanol is 2.00°C/m. What is the freezing point (°C) of a solution prepared by dissolving 40.0 g of glycerin (C₃H₈O₃, a nonelectrolyte) in 200.0 g of ethanol?

The formula weight of FeCl₃^.6H₂O is __________.

The osmotic pressure of a solution formed by dissolving 25.0 mg of aspirin (C₉H₈O₄) in 0.250 L of water at 25°C is __________ atm.