Q: Which of the following is the correct formula for calculating molarity ($$M$$)?

$$M = \frac{\text{mol solute}}{\text{L solution}}$$

Q: Which of the following is the correct formula for calculating parts per million (ppm)?

$$ppm = \frac{\text{g solute}}{\text{g solution}} \times 10^6$

Question 1

A solution is prepared by dissolving 10.0 g of NaCl in enough water to make 500 mL of solution. What is the molarity ($$M) of $$the solution? (Molar mass of NaCl = 58.44 g/mol)

Accepted Answer

$$0.342\ M$$

Question 2

Which of the following best describes the process of osmosis?

Accepted Answer

The movement of solvent molecules from a region of lower solute concentration to a region of higher solute concentration through a semipermeable membrane.

Question 3

A 250 mL sample of a 2.00 M HCl solution is diluted to a final volume of 1.00 L. What is the final concentration of HCl?

Accepted Answer

$$0.500\ M$$

Question 4

Which of the following statements about strong and weak electrolytes is correct?

Accepted Answer

A strong electrolyte completely dissociates into ions in solution, while a weak electrolyte only partially dissociates.

Question 5

Calculate the percent by mass (% w/w) of NaOH in a solution made by dissolving 8.0 g of NaOH in 92.0 g of water.

Accepted Answer

$$8.0\%$$

Question 6

Which of the following will increase the rate of dissolution of a solid solute in a liquid solvent?

Accepted Answer

Increasing the temperature of the solvent.

Question 7

A solution contains 0.0050 g of lead(II) nitrate in 1.0 L of water. What is the concentration in parts per million (ppm)?

Accepted Answer

$$5.0\ ppm$$

Question 8

Which of the following best explains why adding salt to ice causes the ice to melt at a lower temperature?

Accepted Answer

Salt lowers the freezing point of water by disrupting the formation of the solid lattice.

Question 9

Which of the following is the correct formula for calculating molarity ($$M$$)?

Accepted Answer

$$M = \frac{	ext{mol solute}}{	ext{L solution}}$$

Question 10

A chemist needs to prepare 500 mL of a 0.10 M Na$$_2SO$_4$$ solution from a 1.0 M stock solution. What volume of the stock solution should be used?

Accepted Answer

$$50\ mL$$

Question 11

Which of the following is NOT a colligative property?

Accepted Answer

Color of the solution

Question 12

A solution is made by dissolving 2.0 g of glucose (C$$_6H$_{12}O$_6) in $$enough water to make 100 mL of solution. What is the percent by mass (% w/w) of glucose in the solution? (Assume the density of water is 1.0 g/mL.)

Accepted Answer

$$1.96\%$$

Question 13

Which of the following best describes a saturated solution?

Accepted Answer

A solution in which no more solute can dissolve at a given temperature.

Question 14

Which of the following equations is used to calculate the dilution of a solution?

Accepted Answer

$$M_1V_1 = M_2V_2$$

Question 15

Which of the following best explains why sugar dissolves in water?

Accepted Answer

The polar water molecules interact with the polar regions of the sugar molecules, allowing them to separate and disperse.

Question 16

A solution is prepared by mixing 100 mL of 0.20 M NaCl with 100 mL of 0.30 M NaCl. What is the final concentration of NaCl in the mixture?

Accepted Answer

$$0.25\ M$$

Question 17

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

Accepted Answer

The solubility of gases in liquids decreases as temperature increases.

Question 18

Which of the following is the correct formula for calculating parts per million (ppm)?

Accepted Answer

$$ppm = \frac{	ext{g solute}}{	ext{g solution}} 	imes 10^6$

Question 19

Which of the following best describes the activation energy of a chemical reaction?

Accepted Answer

The minimum energy required for a reaction to occur.

Question 20

A patient receives an intravenous (IV) solution that is hypotonic relative to their blood plasma. What is the most likely effect on the patient's red blood cells?

Accepted Answer

Water will enter the cells, causing them to swell and possibly burst.

Solutions, Chemical Reactions, and Aqueous Chemistry: Study Guide for Exam 3

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