Question 1

Which of the following statements best explains why the boiling point of water is much higher than that of methane, even though both are small molecules?

Accepted Answer

Water molecules form hydrogen bonds, which are much stronger than the intermolecular forces present in methane.

Question 2

Which type of intermolecular force is present in all substances, regardless of their polarity?

Accepted Answer

London dispersion forces

Question 3

A sample of ethanol (C$$_2H$_5OH) $$and a sample of dimethyl ether (CH$$_3$$OCH$$_3) $$have similar molar masses. However, ethanol has a much higher boiling point. What is the best explanation for this observation?

Accepted Answer

Ethanol forms hydrogen bonds, while dimethyl ether does not.

Question 4

Which of the following substances is most likely to exhibit significant hydrogen bonding?

Accepted Answer

H$$_2$$NNH$$_2$$

Question 5

The viscosity of a liquid is most directly related to:

Accepted Answer

The strength of its intermolecular forces

Question 6

Which of the following best describes the molecular-level reason why water forms a concave meniscus in a glass tube, while mercury forms a convex meniscus?

Accepted Answer

Water has stronger adhesive forces to glass than cohesive forces between water molecules, while mercury has stronger cohesive forces than adhesive forces to glass.

Question 7

Which of the following phase transitions requires energy to be absorbed by the substance?

Accepted Answer

Vaporization ($$l \rightarrow g)$$

Question 8

What is the formula for pressure, and what does each variable represent?

Accepted Answer

$$p = \frac{F}{A}$$, where $$p is $$pressure, $$F is $$force, and $$A is $$area.

Question 9

Which of the following correctly ranks the strength of intermolecular forces from strongest to weakest?

Accepted Answer

Ion-dipole \u003e Hydrogen bond \u003e Dipole-dipole \u003e London dispersion

Question 10

A phase diagram shows the state of a substance at various pressures and temperatures. What is the significance of the triple point?

Accepted Answer

It is the unique pressure and temperature where solid, liquid, and gas phases are all in equilibrium.

Question 11

Which factor increases the strength of London dispersion forces in a molecule?

Accepted Answer

Increasing the molecular surface area

Question 12

If solid methane at 1 atm is heated while the pressure is held constant, what phase change will occur?

Accepted Answer

It will sublime (solid to gas)

Question 13

Which of the following crystalline solids is most likely to conduct electricity when dissolved in water?

Accepted Answer

Ionic crystalline solid

Question 14

Which property of liquids is defined as the amount of energy required to increase the surface area of a liquid by a unit amount?

Accepted Answer

Surface tension

Question 15

Why does it take less heat to melt ice than to vaporize liquid water?

Accepted Answer

Vaporizing water requires overcoming stronger intermolecular forces than melting ice.

Question 16

Which of the following best describes a supercritical fluid?

Accepted Answer

A state of matter with properties of a gas and liquid at the same time.

Question 17

Which of the following is true about the relationship between temperature and vapour pressure?

Accepted Answer

Vapour pressure increases as temperature increases.

Question 18

Which type of unit cell has a coordination number of 8 and contains 2 atoms per unit cell?

Accepted Answer

Body-centered cubic (bcc)

Question 19

Which of the following is a correct statement about molecular crystalline solids?

Accepted Answer

They are held together by intermolecular forces and have relatively low melting points.

Liquids, Solids, and Intermolecular Forces (Ch. 11): Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard