Question 1

The mole fraction of potassium nitrate in an aqueous solution is 0.0194. The solution's density is 1.0627 g/mL. Calculate the molarity of the solution.

Accepted Answer

Molarity = (moles of solute) / (liters of solution)

First, we need to calculate the moles of potassium nitrate in the solution:

Let's assume that we have 1000 mL of solution:

- The density of the solution is 1.0627 g/mL, so the mass of 1000 mL of solution is:
1.0627 g/mL x 1000 mL = 1062.7 g

- We know that the mole fraction of potassium nitrate in the solution is 0.0194, which means that the moles of potassium nitrate in the solution are:

0.0194 x 1062.7 g / 101.1032 g/mol (the molar mass of KNO3) = 0.2042 moles

Now, we can calculate the molarity of the solution:

- The volume of the solution is 1000 mL = 1 L

- Molarity = 0.2042 moles / 1 L = 0.2042 M  (rounded to 3 significant figures)

Therefore, the best choice is (C) 1.05 M.

Question 2

Copper(II) bromide is used as a wood preservative. What mass of CuBr₂ is needed to prepare 750.0 mL of a 1.25 M solution?

Accepted Answer

1. Calculate the number of moles needed:
Molarity = moles of solute/volume of solution in liters
1.25 M = moles/0.75 L
moles = 0.9375 mol
2. Calculate the mass needed using the molar mass of CuBr2:
0.9375 mol x 223 g/mol = 209 g.

Question 3

A 0.89% (w/v) sodium chloride solution is referred to as physiological saline solution because it has the same concentration of salts as human blood. What is the molarity of a physiological saline solution?

Accepted Answer

The molarity of a solution is defined as the number of moles of solute per liter of solution. To calculate the molarity of a physiological saline solution, we first need to determine the molecular weight of sodium chloride, which is 58.44 g/mol.

Next, we need to convert the percentage concentration to grams per liter. A 0.89% (w/v) solution means that 0.89 g of salt is dissolved in 100 mL of solution (or 0.89 g/100 mL). To convert this to grams per liter, we need to multiply by a conversion factor of 10, since there are 10 deciliters (dL) in a liter:

0.89 g/100 mL x 10 mL/dL = 8.9 g/L

Now we can calculate the molarity of the solution:

Molarity = moles of solute / liters of solution

To determine the number of moles of sodium chloride in 1 liter of a 0.89% solution, we need to divide the mass by the molecular weight:

8.9 g/L / 58.44 g/mol = 0.152 moles/L

Therefore, the molarity of a physiological saline solution is 0.15 M (rounded to two significant figures).

Question 4

Which of the following statements describes the correct method of preparation of 1.00 L of a 2.0 M urea solution? _urea = 60.06 g/mol

Accepted Answer

The answer of Which of the following statements describes the...

Question 5

Potassium hydrogen phosphate is used in the preparation of nondairy powdered creamers. Calculate the molarity of a solution prepared by dissolving 238 g of K₂HPO₄ in enough water to produce 275 mL of solution.

Accepted Answer

The answer of Potassium hydrogen phosphate is used in the...

Question 6

Calcium nitrite is used as a corrosion inhibitor in lubricants. What is the molality of a solution prepared by dissolving 18.5 g of calcium nitrite in 83.5 g of distilled water?

Accepted Answer

The answer of Calcium nitrite is used as a corrosion...

Question 7

Cadmium bromide is used in photography and lithography. Calculate the molality of a solution prepared by dissolving 45.38 g of CdBr₂ in 375.0 g of water.

Accepted Answer

The answer of Cadmium bromide is used in photography and...

Question 8

What is the molality of a solution prepared by dissolving 86.9 g of diethyl ether, C₄H₁₀O, in 425 g of benzene, C₆H₆?

Accepted Answer

The answer of What is the molality of a solution...

Question 9

Sodium hydroxide is a common ingredient in drain cleaners such as Drano. The mole fraction of sodium hydroxide in a saturated aqueous solution is 0.310. What is the molality of the solution?

Accepted Answer

The answer of Sodium hydroxide is a common ingredient in...

Question 10

A solution of ethanol (C₂H₆O) in water is sometimes used as a disinfectant. 1.00 L of this solution contains 553 g of ethanol and 335 g of water. What is the mole fraction of ethanol in this solution?

Accepted Answer

To find the mole fraction of ethanol, we need to first find the moles of ethanol and water in the solution.

Moles of ethanol = (mass of ethanol) / (molar mass of ethanol)
= 553 g / 46.07 g/mol
= 12.01 mol

Moles of water = (mass of water) / (molar mass of water)
= 335 g / 18.02 g/mol
= 18.60 mol

The total moles of solute and solvent in the solution are 12.01 mol + 18.60 mol = 30.61 mol.

The mole fraction of ethanol can be calculated as:

Mole fraction of ethanol = (moles of ethanol) / (total moles of solute and solvent)
= 12.01 mol / 30.61 mol
= 0.392

Therefore, the mole fraction of ethanol in the solution is 0.392, which corresponds to choice B.

Question 11

A solution of ethanol (C₂H₆O) in water is sometimes used as a disinfectant. 1.00 L of this solution contains 553 g of ethanol and 335 g of water. What is the molality of the ethanol in this solution?

Accepted Answer

The answer of A solution of ethanol (C₂H₆O) in water...

Question 12

The solubility of the oxidizing agent potassium permanganate is 7.1 g per 100.0 g of water at 25°C. What is the mole fraction of potassium permanganate in this solution?

Accepted Answer

The answer of The solubility of the oxidizing agent potassium...

Question 13

Isoamyl salicylate (  = 208.25 g/mol) has a pleasant aroma and is used in perfumes and soaps. Which of the following combinations gives a 0.75 m solution of isoamyl salicylate in ethyl alcohol (d = 0.7893 g/mL)?

Accepted Answer

The answer of Isoamyl salicylate (  = 208.25 g/mol)...

Question 14

What volume of concentrated (14.7 M) phosphoric acid is needed to prepare 25.0 L of 3.0 M H₃PO₄?

Accepted Answer

The answer of What volume of concentrated (14.7 M) phosphoric...

Question 15

Calculate the molarity of a solution prepared by diluting 1.85 L of 6.5 M KOH to 11.0 L.

Accepted Answer

M1V1 = M2V2

(6.5 M)(1.85 L) = (M2)(11.0 L)

M2 = 1.1 M

Question 16

What is the mole fraction of Ne in a mixture containing 10.1 g of Ne, 79.9 g of Ar, and 83.8 g of Kr?

Accepted Answer

The answer of What is the mole fraction of Ne...

Question 17

Aqueous ammonia is commercially available in a solution that is 28% (w/w) ammonia. What is the mole fraction of ammonia in such a solution?

Accepted Answer

The answer of Aqueous ammonia is commercially available in a...

Question 18

A 2.0% (w/v) solution of sodium hydrogen citrate, Na₂C₆H₆O₇, which also contains 2.5% (w/v) of dextrose, C₆H₁₂O₆, is used as an anticoagulant for blood which is to be used for transfusions. What is the molarity of the sodium hydrogen citrate in the solution?

Accepted Answer

The answer of A 2.0% (w/v) solution of sodium hydrogen...

Question 19

Saccharin, one of the first non-nutritive sweeteners used in soft-drinks, is 500 times sweeter than sugar in dilute aqueous solutions. The solubility of saccharin is 1.00 gram per 290 mL of solution. What is the molarity of a saturated saccharin solution? (  saccharin = 183.2 g/mol)

Accepted Answer

The answer of Saccharin, one of the first non-nutritive sweeteners...

Question 20

The chemist, Anna Lytic, must prepare 1.00 kg of 15.0% (w/w) acetic acid using a stock solution which is 36.0% (w/w) acetic acid (d = 1.045 g/mL). Which of the following combinations will give her the solution she wants?

Accepted Answer

To prepare 1.00 kg of a 15.0% (w/w) solution, 150 g of acetic acid is needed (15% of 1000 g). Option B correctly uses mass (g) for both acetic acid and water, ensuring the final mixture's mass is 1000 g, with 417 g of 36% acetic acid solution providing the required 150 g of acetic acid (since 36% of 417 g is approximately 150 g).

Quiz 13: The Properties of Mixtures Solutions and Colloids

The mole fraction of potassium nitrate in an aqueous solution is 0.0194. The solution's density is 1.0627 g/mL. Calculate the molarity of the solution.

Copper(II) bromide is used as a wood preservative. What mass of CuBr₂ is needed to prepare 750.0 mL of a 1.25 M solution?

A 0.89% (w/v) sodium chloride solution is referred to as physiological saline solution because it has the same concentration of salts as human blood. What is the molarity of a physiological saline solution?

Which of the following statements describes the correct method of preparation of 1.00 L of a 2.0 M urea solution? _urea = 60.06 g/mol

Potassium hydrogen phosphate is used in the preparation of nondairy powdered creamers. Calculate the molarity of a solution prepared by dissolving 238 g of K₂HPO₄ in enough water to produce 275 mL of solution.

Calcium nitrite is used as a corrosion inhibitor in lubricants. What is the molality of a solution prepared by dissolving 18.5 g of calcium nitrite in 83.5 g of distilled water?

Cadmium bromide is used in photography and lithography. Calculate the molality of a solution prepared by dissolving 45.38 g of CdBr₂ in 375.0 g of water.

What is the molality of a solution prepared by dissolving 86.9 g of diethyl ether, C₄H₁₀O, in 425 g of benzene, C₆H₆?

Sodium hydroxide is a common ingredient in drain cleaners such as Drano. The mole fraction of sodium hydroxide in a saturated aqueous solution is 0.310. What is the molality of the solution?

A solution of ethanol (C₂H₆O) in water is sometimes used as a disinfectant. 1.00 L of this solution contains 553 g of ethanol and 335 g of water. What is the mole fraction of ethanol in this solution?

A solution of ethanol (C₂H₆O) in water is sometimes used as a disinfectant. 1.00 L of this solution contains 553 g of ethanol and 335 g of water. What is the molality of the ethanol in this solution?

The solubility of the oxidizing agent potassium permanganate is 7.1 g per 100.0 g of water at 25°C. What is the mole fraction of potassium permanganate in this solution?

Isoamyl salicylate ( = 208.25 g/mol) has a pleasant aroma and is used in perfumes and soaps. Which of the following combinations gives a 0.75 m solution of isoamyl salicylate in ethyl alcohol (d = 0.7893 g/mL) ?

What volume of concentrated (14.7 M) phosphoric acid is needed to prepare 25.0 L of 3.0 M H₃PO₄?

Calculate the molarity of a solution prepared by diluting 1.85 L of 6.5 M KOH to 11.0 L.

What is the mole fraction of Ne in a mixture containing 10.1 g of Ne, 79.9 g of Ar, and 83.8 g of Kr?

Aqueous ammonia is commercially available in a solution that is 28% (w/w) ammonia. What is the mole fraction of ammonia in such a solution?

A 2.0% (w/v) solution of sodium hydrogen citrate, Na₂C₆H₆O₇, which also contains 2.5% (w/v) of dextrose, C₆H₁₂O₆, is used as an anticoagulant for blood which is to be used for transfusions. What is the molarity of the sodium hydrogen citrate in the solution?

Saccharin, one of the first non-nutritive sweeteners used in soft-drinks, is 500 times sweeter than sugar in dilute aqueous solutions. The solubility of saccharin is 1.00 gram per 290 mL of solution. What is the molarity of a saturated saccharin solution? ( saccharin = 183.2 g/mol)

The chemist, Anna Lytic, must prepare 1.00 kg of 15.0% (w/w) acetic acid using a stock solution which is 36.0% (w/w) acetic acid (d = 1.045 g/mL) . Which of the following combinations will give her the solution she wants?

Quiz 13: The Properties of Mixtures Solutions and Colloids

The mole fraction of potassium nitrate in an aqueous solution is 0.0194. The solution's density is 1.0627 g/mL. Calculate the molarity of the solution.

Copper(II) bromide is used as a wood preservative. What mass of CuBr2 is needed to prepare 750.0 mL of a 1.25 M solution?

A 0.89% (w/v) sodium chloride solution is referred to as physiological saline solution because it has the same concentration of salts as human blood. What is the molarity of a physiological saline solution?

Which of the following statements describes the correct method of preparation of 1.00 L of a 2.0 M urea solution? urea = 60.06 g/mol

Potassium hydrogen phosphate is used in the preparation of nondairy powdered creamers. Calculate the molarity of a solution prepared by dissolving 238 g of K2HPO4 in enough water to produce 275 mL of solution.

Calcium nitrite is used as a corrosion inhibitor in lubricants. What is the molality of a solution prepared by dissolving 18.5 g of calcium nitrite in 83.5 g of distilled water?

Cadmium bromide is used in photography and lithography. Calculate the molality of a solution prepared by dissolving 45.38 g of CdBr2 in 375.0 g of water.

What is the molality of a solution prepared by dissolving 86.9 g of diethyl ether, C4H10O, in 425 g of benzene, C6H6?

Sodium hydroxide is a common ingredient in drain cleaners such as Drano. The mole fraction of sodium hydroxide in a saturated aqueous solution is 0.310. What is the molality of the solution?

A solution of ethanol (C2H6O) in water is sometimes used as a disinfectant. 1.00 L of this solution contains 553 g of ethanol and 335 g of water. What is the mole fraction of ethanol in this solution?

A solution of ethanol (C2H6O) in water is sometimes used as a disinfectant. 1.00 L of this solution contains 553 g of ethanol and 335 g of water. What is the molality of the ethanol in this solution?

The solubility of the oxidizing agent potassium permanganate is 7.1 g per 100.0 g of water at 25°C. What is the mole fraction of potassium permanganate in this solution?

Isoamyl salicylate ( = 208.25 g/mol) has a pleasant aroma and is used in perfumes and soaps. Which of the following combinations gives a 0.75 m solution of isoamyl salicylate in ethyl alcohol (d = 0.7893 g/mL) ?

What volume of concentrated (14.7 M) phosphoric acid is needed to prepare 25.0 L of 3.0 M H3PO4?

Calculate the molarity of a solution prepared by diluting 1.85 L of 6.5 M KOH to 11.0 L.

What is the mole fraction of Ne in a mixture containing 10.1 g of Ne, 79.9 g of Ar, and 83.8 g of Kr?

Aqueous ammonia is commercially available in a solution that is 28% (w/w) ammonia. What is the mole fraction of ammonia in such a solution?

A 2.0% (w/v) solution of sodium hydrogen citrate, Na2C6H6O7, which also contains 2.5% (w/v) of dextrose, C6H12O6, is used as an anticoagulant for blood which is to be used for transfusions. What is the molarity of the sodium hydrogen citrate in the solution?

Saccharin, one of the first non-nutritive sweeteners used in soft-drinks, is 500 times sweeter than sugar in dilute aqueous solutions. The solubility of saccharin is 1.00 gram per 290 mL of solution. What is the molarity of a saturated saccharin solution? ( saccharin = 183.2 g/mol)

The chemist, Anna Lytic, must prepare 1.00 kg of 15.0% (w/w) acetic acid using a stock solution which is 36.0% (w/w) acetic acid (d = 1.045 g/mL) . Which of the following combinations will give her the solution she wants?

Copper(II) bromide is used as a wood preservative. What mass of CuBr₂ is needed to prepare 750.0 mL of a 1.25 M solution?

Which of the following statements describes the correct method of preparation of 1.00 L of a 2.0 M urea solution? _urea = 60.06 g/mol

Potassium hydrogen phosphate is used in the preparation of nondairy powdered creamers. Calculate the molarity of a solution prepared by dissolving 238 g of K₂HPO₄ in enough water to produce 275 mL of solution.

Cadmium bromide is used in photography and lithography. Calculate the molality of a solution prepared by dissolving 45.38 g of CdBr₂ in 375.0 g of water.

What is the molality of a solution prepared by dissolving 86.9 g of diethyl ether, C₄H₁₀O, in 425 g of benzene, C₆H₆?

A solution of ethanol (C₂H₆O) in water is sometimes used as a disinfectant. 1.00 L of this solution contains 553 g of ethanol and 335 g of water. What is the mole fraction of ethanol in this solution?

A solution of ethanol (C₂H₆O) in water is sometimes used as a disinfectant. 1.00 L of this solution contains 553 g of ethanol and 335 g of water. What is the molality of the ethanol in this solution?

What volume of concentrated (14.7 M) phosphoric acid is needed to prepare 25.0 L of 3.0 M H₃PO₄?

A 2.0% (w/v) solution of sodium hydrogen citrate, Na₂C₆H₆O₇, which also contains 2.5% (w/v) of dextrose, C₆H₁₂O₆, is used as an anticoagulant for blood which is to be used for transfusions. What is the molarity of the sodium hydrogen citrate in the solution?