Question 1

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 2

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 3

What is the mole fraction of Ar 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 Ar...

Question 4

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 5

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 6

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

First, we need to use the density of the solution to find the concentration in units of g/mL. Since the density is 1.0627 g/mL, we know that 1 L (1000 mL) of the solution has a mass of 1062.7 g.

Next, we need to use the mole fraction of potassium nitrate to find how many moles of it are present in 1 L of the solution. Since the mole fraction is 0.0194, we know that 1 L of the solution contains 0.0194 moles of potassium nitrate.

Therefore, the molarity is given by:

Molarity = moles of solute / liters of solution

Molarity = 0.0194 mol / 1 L

Molarity = 0.0194 M

So the answer is C, 1.05 M.

Question 7

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

Accepted Answer

To prepare a 2.0 M solution, you need 2 moles of urea per liter of solution. Since the molar mass of urea is 60.06 g/mol, 2 moles weigh 120.12 g. The correct method involves dissolving 120 g of urea in enough distilled water to make the total solution volume 1.00 L, not the total weight or adding it to a pre-measured volume of water.

Question 8

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

Accepted Answer

The mole fraction of potassium permanganate is calculated by dividing the moles of potassium permanganate by the total moles of solute and solvent. The moles of potassium permanganate can be calculated by dividing the mass of potassium permanganate by its molar mass. The moles of water can be calculated by dividing the mass of water by its molar mass. The total moles of solute and solvent is the sum of the moles of potassium permanganate and the moles of water. The mole fraction of potassium permanganate is then calculated as follows:$$	ext{Mole fraction of potassium permanganate} = \frac{	ext{Moles of potassium permanganate}}{	ext{Total moles of solute and solvent}}$$$$=\frac{7.1 	ext{ g} / 158.034 	ext{ g/mol}}{7.1 	ext{ g} / 158.034 	ext{ g/mol} + 100.0 	ext{ g} / 18.015 	ext{ g/mol}}$$$$= 0.0080$$

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

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 11

Isoamyl salicylate (м = 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 correct answer is A because 117.2 g of isoamyl salicylate in 950.0 mL of ethyl alcohol gives a 0.75 m solution.

Question 12

Potassium hydrogen phosphate is used in the preparation of non-dairy 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 13

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 14

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).

Question 15

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? (м_saccharin = 183.2 g/mol)

Accepted Answer

To find the molarity, divide the mass of saccharin by its molar mass to get moles, then divide by the volume in liters: (1.00 g / 183.2 g/mol) / (0.290 L) = 0.0188 M.

Question 16

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

To find the molarity of sodium chloride in the solution, we need to first calculate the molecular weight of NaCl.

NaCl = 23 + 35.5 = 58.5 g/mol

Now, we need to calculate the number of moles of NaCl in 1000 mL of the solution:

0.89 g NaCl / 100 mL x 10 = 0.89 g NaCl / 1000 mL = 0.0153 moles NaCl / L

Therefore, the molarity of the physiological saline solution is:

0.0153 M NaCl x 1 = 0.15 M NaCl / L of solution.

Question 17

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 18

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 19

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

First, we need to calculate the amount of moles of CuBr2 needed using the formula:

moles = M x V

where M is the molarity and V is the volume in liters.

Moles = 1.25 mol/L x 0.75 L = 0.9375 mol

Next, we need to calculate the mass of CuBr2 using its molar mass:

CuBr2 molar mass = atomic mass of Cu + 2 x atomic mass of Br 
= 63.55 g/mol + 2 x 79.90 g/mol 
= 223.35 g/mol

Mass = moles x molar mass 
= 0.9375 mol x 223.35 g/mol 
= 209.1 g

Rounding to the nearest tenth, we get 209 g as our answer.

Question 20

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 in the solution, we need to first calculate the moles of ethanol and water.

Moles of ethanol = 553 g / 46.07 g/mol = 12.00 mol
Moles of water = 335 g / 18.02 g/mol = 18.61 mol

Total moles of solute = 12.00 mol + 18.61 mol = 30.61 mol

Mole fraction of ethanol = moles of ethanol / total moles of solute
= 12.00 mol / 30.61 mol
= 0.392

Therefore, the mole fraction of ethanol in the solution is 0.392. The best choice is B.

Quiz 13: The Properties of Mixtures: Solutions and Colloids

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?

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

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

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.

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.

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

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

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?

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?

Isoamyl salicylate (м = 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) ?

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

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

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?

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? (м_saccharin = 183.2 g/mol)

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?

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?

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

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 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?

Quiz 13: The Properties of Mixtures: Solutions and Colloids

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?

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

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

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.

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.

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

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

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?

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?

Isoamyl salicylate (м = 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) ?

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

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

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?

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? (мsaccharin = 183.2 g/mol)

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?

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?

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

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 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?

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.

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

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

Potassium hydrogen phosphate is used in the preparation of non-dairy powdered creamers. Calculate the molarity of a solution prepared by dissolving 238 g of K₂HPO₄ in enough water to produce 275 mL of 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? (м_saccharin = 183.2 g/mol)

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?

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

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 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?