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widely known pieces of science known to man. The behavior of gases was examined in Chapter 5 of Silberberg's text. In this chapter, properties of the condensed states (liquids and solids) are discussed. Liquids and solids have different properties than gases, in part, because their constituent particles (i.e. molecules) are closer together...which enables intermolecular forces to come into play. From Silberberg: "The balance between [intermolecular] forces and the kinetic energy of the particles give rise to the properties of each state and to phase changes, the changes from one state to another. |
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Chapter 11 Outline
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Breakdown, Discussion & Help With Sample Problems: What You Should Know
11.1 An Overview of Physical States and Phase Changes
New terms included in this section heat of vaporization, heat of fusion, and heat of sublimation. CHEM 200 students should also re-acquaint themselves with two dditional terms: exothermic reactions and endothermic reactions.
11.2 Types of Intermolecular Forces
CHEM 200 students desiring to learn the important aspects of inter- and intra- molecular forces need to look no further than Table 11.2 (p 419).
One of the most important of the intermolecular forces is hydrogen bonding, a topic discussed at length on p 420 and in Sample Problem 11.1.
click here for a few words about SAMPLE PROBLEM 11.1 (page 421)
11.3 Properties of the Liquid State
Surface tension, capillarity, and viscosity are three important properties of liquid state substances--all three are discussed in Section 11.3. Of import here is the way in which the forces listed in Table 11.2 are incorporated into the explanations of these properties.
11.4 Properties of the Solid State
The discussion of the properties of solid state substances, which commences on page 428 and ends on page 444 of Silberberg's text, is lengthy and contains several important details.
Terms to know:
- crystalline solids
- amorphous solids
- unit cell
- coordination number
- packing efficiency
- closest packed structures
- hexagonal closest packing
- cubic closest packing
- atoms/unit cell
Table 11.5 (p 435) lists the five types of crystalline solids (atomic, molecular, ionic, metallic, and network covalent)...along with their characteristics.
Pages 437-443 contain a fact-filled discussion of metallic solids. Several terms are important here, including valence and conduction band, conductor and semiconductor, insulator, superconductivity, network covalent solids, crystal defects and doping. With the emerging importance of materials chemistry, late 20th-century chemistry majors should pay particular attention to these topics.
11.5 Quantitative Aspects of Changes in State
Unlike Section 11.4 , which is nearly bereft of arithmetic, Section 11.5 is chock-full of equations, graphs, and algebra.
Most of the important things to know in this section are depicted in Fig 11.33 (p 445), which shows what happens when a 2.5 mol sample of water as it changes from gaseous water at 1 atm adn 130oC tooice at -40oC.
The necessary calcuations that enable determination of the energy released for the above process are outlined on pages 445-447.
Vapor pressure is another definition of import to CHEM 200 students, especially in the context of the Clausius-Clapeyron equation (p 449), which relates vapor pressure and temperature for liquid state substances.
click here for a few words about SAMPLE PROBLEM 11.4 (page 449)
The definition of a given liquid's boiling point given in this section (p 450)--"the temperature at which the vapor pressure equals the external pressure" is one that demands understanding of vapor pressure.
Fig 11.39 depicts two phase diagrams--one for carbon dioxide and one for water. CHEM 200 students should familiarize themselves with phase diagrams and what is contained within them...including a given substances critical point and triple point.
Among the aspects of water discussed in this section include its solvent properties, its thermal properties, its surface properties and its density. Section 11.6 makes for good reading...as water ubiquitous nature demands that it be a substantial part of CHEM 200.
exercises such as numbers 11.5, 11.17, 11.32, 11.50, 11.82 and 11.90 are all straightforward problems of the type that are often found on CHEM 200 exams