Question 1

Which of the following best describes the difference between a crystalline solid and an amorphous solid?

Accepted Answer

A crystalline solid has a regular, repeating arrangement of particles, while an amorphous solid lacks long-range order.

Question 2

Which of the following intermolecular forces is primarily responsible for the unusually high boiling point of water ($$H_2O$$)?

Accepted Answer

Hydrogen bonding

Question 3

A sample of ethanol ($$C_2H_5OH) is $$placed in a closed container. Which process occurs when the rate of evaporation equals the rate of condensation?

Accepted Answer

Dynamic equilibrium

Question 4

Which of the following statements about vapor pressure is correct?

Accepted Answer

Vapor pressure increases as temperature increases.

Question 5

A liquid boils when its vapor pressure equals which of the following?

Accepted Answer

The external (atmospheric) pressure

Question 6

Which of the following best explains why salt ($$NaCl) is $$often spread on icy roads in winter?

Accepted Answer

Salt lowers the freezing point of water, causing ice to melt at lower temperatures.

Question 7

Which equation correctly represents the Clausius-Clapeyron equation for the relationship between vapor pressure and temperature?

Accepted Answer

$$\ln P = -\frac{\Delta H_{vap}}{R} \cdot \frac{1}{T} + C$$

Question 8

A solution is prepared by dissolving $$10.0 g of $$glucose ($$C_6H_{12}O_6$) in 100.0$ g of water. Which colligative property will be affected by the addition of glucose?

Accepted Answer

Boiling point elevation

Question 9

Which of the following is a correct statement about the phase diagram of carbon dioxide ($$CO_2$$)?

Accepted Answer

$$CO_2$$ sublimes at atmospheric pressure because its triple point is above 1 atm.

Question 10

Which of the following best describes the process of sublimation?

Accepted Answer

A solid changing directly to a gas without passing through the liquid phase.

Question 11

A sample of ice at $$0^\circC is $$added to $$100 g of $$water at $$50^\circC. $$Which of the following best describes what happens?

Accepted Answer

The ice absorbs heat and melts, lowering the temperature of the water.

Question 12

Which of the following is the best explanation for why oil and water do not mix?

Accepted Answer

Water is polar and oil is nonpolar, so their intermolecular forces are not compatible.

Question 13

Which of the following is the correct expression for the freezing point depression of a solution?

Accepted Answer

$$\Delta T_f = iK_f m$$

Question 14

A solution is made by dissolving $$0.5$$ mol of $$NaCl in$$ $$1.0 kg of $$water. If the van't Hoff factor ($$i) $$for $$NaCl is$$ $$2$$, what is the molality of particles in the solution?

Accepted Answer

$$1.0$$ mol/kg

Question 15

Which of the following best describes the critical point on a phase diagram?

Accepted Answer

The temperature and pressure above which a substance cannot exist as a liquid.

Question 16

Which of the following is a real-life application of colligative properties?

Accepted Answer

Using antifreeze in car radiators to prevent freezing in winter.

Question 17

Which of the following statements about ionic solids is correct?

Accepted Answer

Ionic solids have high melting points due to strong electrostatic forces between ions.

Question 18

Which of the following best explains why the boiling point of $$NH_3 is $$higher than that of $$PH_3$$?

Accepted Answer

$$NH_3$$ forms hydrogen bonds, while $$PH_3$$ does not.

Question 19

A sample of $$H_2O is $$heated from $$-10^\circC to$$ $$110^\circC at 1 $$atm. Which of the following processes does NOT occur during this heating?

Accepted Answer

Deposition

Question 20

Which of the following is the best definition of a supercooled liquid?

Accepted Answer

A liquid cooled below its freezing point without solidifying.

Liquids, Solids, and Intermolecular Forces (Chapter 12) – Study Notes

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