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 occurs only 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: $$\frac{P_1$ V_1$}{T_1$} = \frac{P_2$ V_2$}{T_2$})$$

Accepted Answer

$$V_2 = 1.04$$\ \mathrm{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 colloid?

Accepted Answer

Particles are invisible to the naked eye and do not scatter light.

Question 5

A solution is prepared by dissolving 10.0 g of NaCl in enough water to make 250 mL of solution. What is the molarity of the solution? ($$\mathrm{M} = \frac{	ext{mol solute}}{	ext{L solution}}$$, molar mass NaCl = 58.44 g/mol)

Accepted Answer

$$0.684\ \mathrm{M}$$

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 center while interacting with water on the outside.

Question 7

Which of the following is a correct dissociation equation for the strong electrolyte Na$$_2SO$_4 in $$water?

Accepted Answer

$$\mathrm{Na_2SO_4\ (aq)} \rightarrow 2\ \mathrm{Na^+\ (aq)} + \mathrm{SO_4$^{2-}\ (aq)}$$

Question 8

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 9

Which of the following is the correct expression for the equilibrium constant $$K_{eq}$$ for the reaction $$\mathrm{N_2$\ (g) + 3H_2\ (g) \rightleftharpoons 2NH_3\ (g)}$$?

Accepted Answer

$$K_{eq} = \frac{[NH_3$]^2}{[N_2$][H_2$]^3}$$

Question 10

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

Accepted Answer

HNO$$_2$$

Question 11

A solution is made by diluting 50.0 mL of 2.00 M HCl to a final volume of 250.0 mL. What is the final concentration? (Use $$C_1V_1 = C_2V_2)$$

Accepted Answer

$$0.400\ \mathrm{M}$$

Question 12

Which of the following best describes the difference between a saturated and an unsaturated solution?

Accepted Answer

A saturated solution contains the maximum amount of solute that can dissolve at a given temperature; an unsaturated solution can dissolve more solute.

Question 13

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

Accepted Answer

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

Question 14

Which of the following best describes facilitated transport across a cell membrane?

Accepted Answer

It is a passive process that uses membrane proteins to move substances down their concentration gradient.

Question 15

Which of the following is the correct dissociation equation for acetic acid (a weak acid) in water?

Accepted Answer

$$\mathrm{CH_3COOH\ (aq)} + \mathrm{H_2O\ (l)} \rightleftharpoons \mathrm{CH_3COO^-\ (aq)} + \mathrm{H_3O^+\ (aq)}$$

Question 16

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

Accepted Answer

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

Question 17

Which of the following is the correct expression for the autoionization of water and its equilibrium constant at 25°C?

Accepted Answer

$$\mathrm{H_2O\ (l)} ightleftharpoons \mathrm{H^+\ (aq)} + \mathrm{OH^-\ (aq)}$$

$$K_w = [H^+][OH^-] = 1.0 	imes 10$$^{-14}$$

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 to counteract the disturbance and restore 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

Guida di studio - Domande di pratica

Study guide - Flashcard