Question 1

Which of the following statements best describes the difference between London dispersion forces and hydrogen bonding?

Accepted Answer

London dispersion forces are present in all molecules due to temporary dipoles, while hydrogen bonding is a special, stronger interaction that occurs when hydrogen is bonded to N, O, or F.

Question 2

A sample of gas occupies 2.50 L at 1.00 atm and 300 K. If the pressure is increased to 2.00 atm and the temperature is decreased to 250 K, what is the new volume of the gas? (Use the combined gas law: $$\frac{P_1V_1}{T_1$} = \frac{P_2V_2}{T_2$})$$

Accepted Answer

$$V_2 = 1.04$$\ 	ext{L}$$

Question 3

Which of the following best explains why oil does not dissolve in water?

Accepted Answer

Oil molecules are nonpolar and water molecules are polar, so the intermolecular forces between them are not compatible.

Question 4

Which of the following is NOT a property of a solution?

Accepted Answer

The solute particles can be separated by filtration.

Question 5

A 250 mL solution contains 5.0 g of NaCl. What is the mass/volume percent ($$\frac{	ext{mass of solute}}{	ext{volume of solution}} 	imes 100\%) of $$NaCl in the solution?

Accepted Answer

$$2.0\%$$

Question 6

Which of the following best describes the function of soap molecules in cleaning?

Accepted Answer

Soap molecules are amphipathic, allowing them to form micelles that trap nonpolar dirt and grease in their nonpolar centers while interacting with water through their polar heads.

Question 7

Which of the following is the correct dissociation equation for the strong electrolyte NaCl in water?

Accepted Answer

$$\mathrm{NaCl}(s) \rightarrow \mathrm{Na}^+(aq) + \mathrm{Cl}^-(aq)$$

Question 8

A solution is prepared by diluting 10.0 mL of a 2.0 M NaOH solution to a final volume of 100.0 mL. What is the final concentration? (Use $$C_1V_1 = C_2V_2)$$

Accepted Answer

$$0.20\ \mathrm{M}$$

Question 9

Which of the following best describes the effect of increasing temperature on the solubility of a gas in water?

Accepted Answer

The solubility of a gas in water decreases as temperature increases.

Question 10

Which of the following is a correct statement about the lipid bilayer of cell membranes?

Accepted Answer

The hydrophobic tails of phospholipids face inward, away from water, while the hydrophilic heads face outward toward the aqueous environment.

Question 11

Which of the following is the correct expression for the equilibrium constant ($$K_{eq}) $$for the reaction $$aA + bB \rightleftharpoons cC + dD$$?

Accepted Answer

$$K_{eq} = \frac{[C]^c[D]^d}{[A]^a[B]^b}$$

Question 12

Which of the following acids is NOT one of the seven strong acids?

Accepted Answer

$$\mathrm{HNO}_2$$

Question 13

A buffer solution is prepared using acetic acid ($$\mathrm{CH}_3\mathrm{COOH}) $$and sodium acetate ($$\mathrm{CH}_3\mathrm{COONa}). $$Which of the following best describes how this buffer resists changes in pH when a small amount of acid is added?

Accepted Answer

The acetate ion reacts with the added $$\mathrm{H}^+ to $$form more acetic acid, minimizing the change in pH.

Question 14

Which of the following is the correct formula for calculating pH from $$[H^+]$$?

Accepted Answer

$$\mathrm{pH} = -\log [H^+]$$

Question 15

Which of the following best describes the process of osmosis?

Accepted Answer

The movement of water across a semipermeable membrane from a region of low solute concentration to a region of high solute concentration.

Question 16

A patient receives an intravenous solution that is hypertonic relative to their blood plasma. What is the most likely effect on their red blood cells?

Accepted Answer

Water will leave the cells, causing them to shrink (crenation).

Question 17

Which of the following is the correct dissociation equation for the weak acid acetic acid ($$\mathrm{CH}_3\mathrm{COOH}) in $$water?

Accepted Answer

$$\mathrm{CH}_3\mathrm{COOH}(aq) + \mathrm{H}_2\mathrm{O}(l) \rightleftharpoons \mathrm{CH}_3\mathrm{COO}^-(aq) + \mathrm{H}_3\mathrm{O}^+(aq)$$

Question 18

Which of the following best describes Le Châtelier’s Principle?

Accepted Answer

If a system at equilibrium is disturbed, the system will shift in a direction that minimizes the disturbance and restores equilibrium.

Question 19

Which of the following is the correct formula for calculating the number of equivalents in a solution?

Accepted Answer

$$	ext{Equivalents} = 	ext{moles} 	imes 	ext{charge}$$

CHEM 1150 Exam 4 Study Guide: States of Matter, Solution Chemistry, and Acids/Bases

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