7

Liquids, Solids,
and Phase Changes

These skills are usually tested on the SAT Subject Test in Chemistry. You should be able to . . .

• Describe the states of matter (solids, liquids, and gases).
• Describe and compare the important properties of solids, liquids, and gases.
• Describe the various types of phase change.
• Analyze a phase diagram.
• Explain the use of liquid water as a common solvent.
• Solve solubility and concentration problems.
• Solve colligative property problems in a qualitative manner.
• Describe the continuum of water mixtures, including solutions, colloids, and suspensions.

This chapter will review and strengthen these skills. Be sure to do the Practice Exercises at the end of the chapter.

Liquids and solids are considered condensed phases of matter. By itself, this is a significant differentiation from the phase of matter called a gas, which was discussed extensively in Chapter 5. But there are many other important characteristics that distinguish solids and liquids from gases as well as those that distinguish solids from liquids. Macroscopically (i.e., in a form visible to the naked eye), there are several ways to differentiate solids, liquids, and gases. But in order to understand the states of matter well, and in addition how they change from one to another, it is important to be able to envision these phases from a mind’s-eye perspective that takes into account what they are like on an atomic/molecular level.