Question 1

Benzene has a higher vapor pressure than toluene at the same temperature. Which compound has the higher boiling point?

Accepted Answer

Toluene

Question 2

If 10.0 grams of ethanol (C$_2$H$_5$OH$, M = 46.07$ g/mol) are mixed with 15 grams of water (M = 18.02 g/mol), what is the mole fraction of ethanol in the solution?

Accepted Answer

$X_{	ext{ethanol}} = 0.21$

Question 3

Which of the following, when 10.0 g is dissolved in 1 L of water, will result in the lowest freezing point for the solution?

Accepted Answer

CaCl$_2$

Question 4

A supercritical fluid is best described as:

Accepted Answer

A substance at a temperature and pressure above its critical point, where it exhibits properties of both liquids and gases.

Question 5

If the human eye has an osmotic pressure of $8.00$ atm at $25^\circ$C, what molarity of solute particles in water will provide an isotonic eye drop solution? ($R = 0.08206$ L·atm·mol$^{-1}$·K$^{-1}$)

Accepted Answer

$M = 0.32$ mol/L

Question 6

A solution of sodium chloride has a density of $1.08$ g/mL. The freezing point of pure water is $0.00^\circ$C, and the freezing point depression constant $K_f$ for water is $1.86$ $^\circ$C·kg/mol. What is the percent composition by mass of NaCl in a solution that freezes at $-2.79^\circ$C?

Accepted Answer

20.1%

Question 7

What volume of ethylene glycol, a nonvolatile solute, must be added to $12,503.2$ g of water to produce an antifreeze solution with a freezing point of $-25.0^\circ$C? (The density of ethylene glycol is $1.08$ g/mL, and the molar mass is $62.07$ g/mol. $K_f$ for water is $1.86$ $^\circ$C·kg/mol.)

Accepted Answer

$V = 11,264$ mL

Question 8

Why does molecule A have a higher boiling point than molecule B?

Accepted Answer

Stronger Hydrogen Bonding

Question 9

Between these two arrangements of a molecule, which has stronger intermolecular forces (IMFs)?

Accepted Answer

Molecule C: Stronger dipole-dipole interaction

Question 10

Refer to the phase diagram of methanol. At what temperature and pressure does methanol become a supercritical fluid?

Accepted Answer

$T_c = 240^\circ$C, $P_c = 1,140$ psi

Question 11

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 equilibrium between solid and liquid phases.

Question 12

Which colligative property is most relevant when designing intravenous (IV) solutions for medical use?

Accepted Answer

Osmotic pressure

Question 13

A solution is prepared by dissolving 10.0 g of NaCl in 500 g of water. What is the expected freezing point of the solution? ($K_f$ for water = $1.86$ $^\circ$C·kg/mol, NaCl dissociates completely)

Accepted Answer

$-0.64^\circ$C

Question 14

Which of the following statements about vapor pressure is correct?

Accepted Answer

A liquid with stronger intermolecular forces will have a lower vapor pressure at a given temperature.

Question 15

Which of the following best describes the relationship between boiling point and vapor pressure?

Accepted Answer

A higher vapor pressure at a given temperature means a lower boiling point.

Question 16

Which of the following would increase the boiling point of water the most?

Accepted Answer

Adding a nonvolatile solute such as ethylene glycol

Question 17

Which of the following is NOT a colligative property?

Accepted Answer

Viscosity

Question 18

A solution is made by dissolving 20.0 g of glucose (C$_6$H$_{12}$O$_6$, M = 180.16 g/mol) in 500 g of water. What is the molality of the solution?

Accepted Answer

$0.22$ mol/kg

Question 19

Which of the following best explains why ethylene glycol is used as antifreeze in car engines?

Accepted Answer

It lowers the freezing point and raises the boiling point of water, preventing engine damage in extreme temperatures.

General Chemistry Study Guidance: Colligative Properties, Intermolecular Forces, and Phase Diagrams

Study Guide - Practice Questions

Study Guide - Flashcards