Q: A solution is prepared by dissolving 10.0 g of NaCl in 100.0 g of water. What is the mass percent of NaCl in the solution?

$$\displaystyle \frac{10.0}{110.0} \times 100 = 9.09\%$$

Q: Which of the following is the correct formula for mole fraction ($$\chi) of a $$component in a solution?

$$\chi = \frac{\text{moles of component}}{\text{total moles of all components}}$$

Question 1

Which of the following best describes a solution?

Accepted Answer

A homogeneous mixture of two or more pure substances.

Question 2

Which intermolecular force is primarily responsible for the solubility of NaCl in water?

Accepted Answer

Ion-dipole interactions

Question 3

When ammonium nitrate ($$\mathrm{NH_4NO_3}) $$dissolves in water, the solution feels cold. What does this indicate about $$\Delta H_{soln}$$?

Accepted Answer

$$\Delta H_{soln} is $$positive (endothermic)

Question 4

Which of the following statements about saturated solutions is correct?

Accepted Answer

A saturated solution is in dynamic equilibrium with undissolved solute.

Question 5

Which of the following best explains why oil and water do not mix?

Accepted Answer

Oil is nonpolar and water is polar, so there are no strong attractive forces between them.

Question 6

A solution is prepared by dissolving 10.0 g of NaCl in 100.0 g of water. What is the mass percent of NaCl in the solution?

Accepted Answer

$$\displaystyle \frac{10.0}{110.0} 	imes 100 = 9.09\%$$

Question 7

Which of the following will increase the solubility of a gas in a liquid?

Accepted Answer

Increasing the partial pressure of the gas above the liquid

Question 8

Which vitamin would you expect to be more readily stored in fatty tissue, based on its structure?

Accepted Answer

Vitamin A, because it is largely nonpolar

Question 9

A solution is made by dissolving 0.50 mol of glucose in 1.0 kg of water. What is the molality of the solution?

Accepted Answer

$$0.50\ \mathrm{m}$$

Question 10

Which of the following equations correctly expresses the relationship for osmotic pressure ($$\Pi) of a $$solution?

Accepted Answer

$$\Pi = iMRT$$

Question 11

A 2.00 molal aqueous solution of sucrose ($$i=1) is $$prepared. If the boiling point elevation constant for water is $$K_b = 0.51\ ^\circ\mathrm{C}/m$$, what is the boiling point of the solution?

Accepted Answer

$$101.02\ ^\circ\mathrm{C}$$

Question 12

Which of the following statements about colligative properties is true?

Accepted Answer

They depend only on the number of solute particles.

Question 13

A solution is prepared by dissolving 0.250 g of a nonvolatile, nonelectrolyte solute in 40.0 g of CCl$$_4. $$The boiling point of the solution is $$0.357\ ^\circ\mathrm{C}$$ higher than that of pure CCl$$_4$$ ($$K_b = 5.02\ ^\circ\mathrm{C}/m). $$What is the molar mass of the solute?

Accepted Answer

$$143\ \mathrm{g/mol}$$

Question 14

Which of the following best describes a supersaturated solution?

Accepted Answer

A solution that contains more solute than is normally possible at a given temperature.

Question 15

Which of the following will increase the solubility of a solid solute in water in most cases?

Accepted Answer

Increasing the temperature

Question 16

Which of the following is the correct formula for mole fraction ($$\chi) of a $$component in a solution?

Accepted Answer

$$\chi = \frac{	ext{moles of component}}{	ext{total moles of all components}}$$

Question 17

A solution is prepared by dissolving 3.86 g of glucose ($$\mathrm{C_6H_{12}O_6$}$$, molar mass = 180.12 g/mol) in 155 mL of ethanol (density = 0.789 g/mL). What is the molality of the solution?

Accepted Answer

$$0.175\ \mathrm{m}$$

Question 18

Which of the following is NOT a colligative property?

Accepted Answer

Color change

Question 19

Which of the following best explains why cold rivers have higher oxygen content than warm rivers?

Accepted Answer

The solubility of gases in water decreases as temperature increases.

Properties of Solutions: Structure, Formation, and Colligative Properties

Guida di studio - Domande di pratica

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