Question 1

Which type of intermolecular attractive force is expected to be the strongest in a sample of CH$$_3$$COOH (acetic acid)?

Accepted Answer

Hydrogen bonding

Question 2

Given the following substances, which one is most likely to exhibit only London dispersion forces as its primary intermolecular attraction?

Accepted Answer

Cl$$_2 ($$chlorine gas)

Question 3

A sample of water at 100$$^	ext{o}C $$and 1 atm is heated at constant pressure. What phase change will occur, and what is the enthalpy change associated with this process?

Accepted Answer

Vaporization; $$\Delta H_{vap}$$

Question 4

The atmospheric pressure in Albuquerque is approximately 680 mm Hg. If water boils at 100$$^	ext{o}C at 1 $$atm, what will happen to the boiling point of water in Albuquerque?

Accepted Answer

It will be lower than 100$$^	ext{o}C$$

Question 5

Which of the following statements best explains why NaCl (sodium chloride) has a much higher melting point than HCl (hydrogen chloride)?

Accepted Answer

NaCl is held together by ionic bonds, which are much stronger than the dipole-dipole forces in HCl.

Question 6

Refer to the phase diagram shown. What is the significance of the point marked 'C'?

Accepted Answer

It is the critical point, above which the liquid and gas phases are indistinguishable.

Question 7

If a substance is at a temperature and pressure above its critical point, what phase does it exist in?

Accepted Answer

Supercritical fluid

Question 8

Which of the following best describes the process of sublimation?

Accepted Answer

Transition from solid to gas

Question 9

A heating curve for water shows a plateau at 0$$^	ext{o}C $$and another at 100$$^	ext{o}C. $$What does the plateau at 100$$^	ext{o}C $$represent?

Accepted Answer

The temperature at which water boils and undergoes a phase change from liquid to gas

Question 10

Which of the following substances would you expect to have the highest boiling point?

Accepted Answer

CH$$_3$$COOH

Question 11

If the pressure is decreased at a constant temperature, which phase transition is most likely to occur for a liquid?

Accepted Answer

Vaporization

Question 12

Which equation correctly relates the pressure and temperature at which a liquid boils?

Accepted Answer

$$P_{atm} = P_{vap}$$

Question 13

Which of the following is true about the triple point of a substance?

Accepted Answer

It is the temperature and pressure where solid, liquid, and gas phases coexist in equilibrium.

Question 14

Which intermolecular force is responsible for the high boiling point of water compared to other group 16 hydrides?

Accepted Answer

Hydrogen bonding

Question 15

A sample of ice is heated at 1 atm pressure. At what temperature does the phase change from solid to liquid occur, and what is the enthalpy change called?

Accepted Answer

0$$^	ext{o}C$$; $$\Delta H_{fus}$$

Question 16

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

Accepted Answer

As atmospheric pressure increases, boiling point increases.

Question 17

Which of the following substances is most likely to sublime under standard conditions?

Accepted Answer

Dry ice (solid CO$$_2)$$

Question 18

Which of the following phase changes is endothermic?

Accepted Answer

Vaporization

Question 19

A phase diagram shows a region labeled 'B'. If a substance is in region B, what phase is it in?

Accepted Answer

Liquid

Question 20

Which of the following best explains why the boiling point of water is lower in Albuquerque than at sea level?

Accepted Answer

The atmospheric pressure is lower, so water boils at a lower temperature.

Intermolecular Forces and Phase Diagrams: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards