Q: Which equation is used to calculate the mass percent of a solute in a solution?

$$\text{mass percent} = \frac{\text{mass solute}}{\text{mass solute} + \text{mass solvent}} \times 100$$

Q: Which of the following is the correct formula for calculating molarity?

$$\text{Molarity} = \frac{\text{moles solute}}{\text{liters solution}}$$

Question 1

Which of the following best explains why the carbon dioxide at the bottom of Lake Nyos was able to reach such a high concentration before being released?

Accepted Answer

The pressure at the bottom of the lake was very high, increasing the solubility of carbon dioxide in water.

Question 2

Which of the following is the best definition of a solution?

Accepted Answer

A homogeneous mixture of two or more substances.

Question 3

Which statement correctly describes the relationship between temperature and the solubility of solids in water?

Accepted Answer

The solubility of solids in water increases with increasing temperature.

Question 4

A solution is prepared by dissolving 15.5 g of NaCl in enough water to make 1.50 L of solution. What is the molarity of the solution? (Molar mass of NaCl = 58.44 g/mol)

Accepted Answer

$$0.177\,M$$

Question 5

Which of the following best describes why warm soda pop fizzes more than cold soda pop?

Accepted Answer

The solubility of carbon dioxide gas decreases with increasing temperature.

Question 6

Which of the following is an example of an electrolyte solution?

Accepted Answer

A solution of NaCl in water.

Question 7

A water sample contains 8.5% carbon dioxide by mass. If you have 2860 g of this solution, how many grams of carbon dioxide does it contain?

Accepted Answer

$$242\,g$$

Question 8

Which of the following statements about solubility is correct?

Accepted Answer

Polar molecular solids, such as table sugar, are usually soluble in water.

Question 9

Which equation is used to calculate the mass percent of a solute in a solution?

Accepted Answer

$$	ext{mass percent} = \frac{	ext{mass solute}}{	ext{mass solute} + 	ext{mass solvent}} 	imes 100$$

Question 10

A chemist needs to prepare 5.00 L of a 1.50 M KCl solution from a 12.0 M stock solution. What volume of the stock solution is required?

Accepted Answer

$$0.625\,L$$

Question 11

Which of the following best describes a supersaturated solution?

Accepted Answer

A solution that holds more than the normal maximum amount of dissolved solute.

Question 12

Which of the following is true about the dissolution of NaCl in water?

Accepted Answer

The Na+ and Cl- ions are surrounded by water molecules and dispersed throughout the solution.

Question 13

Which of the following best explains why the tragedy at Lake Nyos was so deadly?

Accepted Answer

The carbon dioxide released was heavier than air and displaced oxygen in the valley.

Question 14

Which of the following is the correct formula for calculating molarity?

Accepted Answer

$$	ext{Molarity} = \frac{	ext{moles solute}}{	ext{liters solution}}$$

Question 15

A 1.50 M solution of $$	ext{Na}_3	ext{PO}_4$$ contains what concentration of $$	ext{Na}^+$$ ions?

Accepted Answer

$$4.50\,M$$

Question 16

Which of the following statements about solution stoichiometry is correct?

Accepted Answer

The volume and concentration of a solution can be used to calculate the number of moles of reactant for stoichiometric calculations.

Question 17

Which of the following best describes the process of recrystallization?

Accepted Answer

A solid is dissolved in a solvent at an elevated temperature, and as the solution cools, pure crystals form.

Question 18

Which of the following statements about the solubility of gases in liquids is correct?

Accepted Answer

The solubility of gases in liquids decreases with increasing temperature.

Chapter 13: Solutions – Study Notes for Introductory Chemistry

Guida di studio - Domande di pratica

Study guide - Flashcard