Chapter 13 Solids and Liquids

Question 1

The electrostatic attractions between molecules are called _____________.

Answer 1

Intermolecular Forces

Question 2

Rank the intermolecular bonds in increasing strength (Weakest to Strongest).

Answer 2

London-Dispersion, Dipole-Dipole, and Hydrogen Bonds.

Question 3

List three true statements about evaporation.

Answer 3

It’s a cooling process, it can occur at any temperature, and it is a surface phenomenon.

Question 4

To solidify gas such as hydrogen, there must be a ___________ temperature and a ____________ pressure.

Answer 4

Low, High

Question 5

A crystal’s strength is determined by ________________.

Answer 5

Electrical charge, Particle charge, and Geometric structure.

Question 6

Use the terms kinetic-molecular theory, temperature decreases, and viscosity in one paragraph that clearly relates them.

Answer 6

According to the kinetic-molecular theory, as temperature decreases, the movement of the molecules also decreases. This decreased movement allows the intermolecular forces to play a stronger role in binding particles together, increasing viscosity.

Question 7

Explain why water droplets tend to be spherical

Answer 7

The shape is a result of the intermolecular attractions between water molecules. They pull it into the shape with the least surface area per unit of volume (spheres).

Question 8

A detergent is considered a(n) __________ because it interferes with the normal surface tension of water.

Answer 8

Surfactant

Question 9

Predict the type of intermolecular forces between O², HBr, and HCl.

Answer 9

O²= Dispersion
HBr= Dipole, Dispersion
HCl= Dipole, Dispersion

Question 10

When vaporization occurs in a non-boiling liquid, it is called ______________.

Answer 10

Evaporation

Question 11

Would you expect a crystalline solid or a amorphous solid to have a sharp melting point?

Answer 11

Crystalline Solid

Question 12

How are liquids similar to gases?

Answer 12

Fluidity, Diffusibility, and Permeability.

Question 13

Hydrogen bonds can occur between molecules containing hydrogen atoms and __________, ____________, and ____________

Answer 13

Fluorine, Nitrogen, and Oxygen.

Question 14

The main intermolecular force that exist between only polar molecules is _________________.

Answer 14

Dipole- Dipole Forces

Question 15

What happens to the temperature of a sample of ice at its melting point as it melts?

Answer 15

Temperature remains constant.

Question 16

During phase changes, the temperature of a substance _______________.

Answer 16

Remains the same.

Question 17

The state of matter that is fairly dense, has a definite volume, and has a fixed shape is a(n) _____________.

Answer 17

Solid

Question 18

What is the term of the survey surface of a liquid?

Answer 18

Meniscus

Question 19

What do we call the smallest unit of a crystal that can be used as a building block?

Answer 19

Unit Cell

Question 20

The process by which mixtures can be separated using vaporization and condensation is called ______________.

Answer 20

Distillation

Question 21

What is the critical temperature?

Answer 21

Highest temperature at which the substance can exist as a liquid and coexist with its vapor phase (highest temperature).

Question 22

The reason that alcohol evaporates much faster than mercury does is due to a difference in ______________.

Answer 22

Vapor Pressure

Question 23

Lattice energy is always expressed as a ___________ number.

Answer 23

Negative

Question 24

On the basis of the bonds within each molecule, ____________ have low melting points.

Answer 24

Nonpolar

Question 25

NaCl crystals are classified as __________ crystals

Answer 25

Ionic

Question 26

Name two factors that effect the strength of a crystal lattice.

Answer 26

Magnitude of electrical changes, size of particles, and structure of crystal.

Question 27

What do we call the pressure exerted by evaporated molecules over a liquid?

Answer 27

Vapor Pressure

Question 28

Solids with no distinct shape or underlying pattern are called _____________.

Answer 28

Amorphous

Question 29

(T or F) Gases that have critical temperatures above room temperature can be liquefied by pressure alone.

Answer 29

True

Question 30

(T or F) Ionic crystalline solids are described as cations surrounded by a sea of mobile valence electrons.

Answer 30

False

Question 31

(T or F) While a substance melts, it's temperature remains constant.

Answer 31

True

Question 32

(T or F) The pressure extorted by evaporated molecules over a liquid is called vapor pressure.

Answer 32

True

Question 33

(T or F) Lattice energy is defined as the amount of energy required to dissolve a crystal.

Answer 33

False

Question 34

(T or F) Dipole-dipole forces between molecules are weaker than the electrostatic forces between ions in a crystal

Answer 34

True

Question 35

The direct change from solid to gas.

Answer 35

Sublimation

Question 36

The attraction between particles of liquid.

Answer 36

Cohesion

Question 37

The change that results in formation of frost and snow.

Answer 37

Deposition

Question 38

The attraction of particles of a liquid to the particles of another material.

Answer 38

Adhesion

Question 39

The change from liquid to gas when vapor pressure equals atmosphere pressure.

Answer 39

Boiling