APChemGases

The Chemistry and Physics of Gases

The behavior of molecules in the gas state can be modeled quite accurately. Chapter 10 in Brown, LeMay, and Burston presents a clear, concise, and thorough summary of the laws governing gases. This material can be reviewed independently by AP Chemistry students, strengthening your understanding of chemicals while also giving you many opportunities to practice mental math, significant digits, and units.

The table below presents a seven-part review of this chapter. Ultimately, you should study the entire chapter. Each table and figure is worth your time, and don't forget to read carefully the chapter summary on pages 397 and 398. A strong AP Chemistry student will understand every word in the chapter summary.

You can earn AP test points for your efforts. Read the material below to find out how.

Good luck in your review of gas behavior!


 * Part || Sections in Brown LeMay ||= Summary of Ideas || Practice Problems ||
 * I. || 10.1 and 10.2 || Four variables are usually used to describe a sample of gas: volume, temperature, moles, and pressure. Of these, pressure is perhaps the most challenging, and section 10.2 reviews the definition of this unit as well as its measurement. Review how a barometer works and teach yourself how to read a manometer. Question 10.15 is a typical example of the information that can be determined from a manometer. || 10.7, 10.9, 10.15, 10.16 pages 398 & 399 ||
 * II. || 10.3 || The relationships between the four variables - P, V, n, T - can be discovered fairly easily. Keep n and T constant, and you will find that P and V vary inversely. This relationship is known as Boyle's law. Section 10.3 reviews three important relationships and derives the formulas like P1 V1 = P2 V2. Now is a good time to find your notes from last spring on these relationships. || 10.19 and 10.21 pages 399 & 400, 10.83 page 403 ||
 * III. || 10.4 || This section looks a lot like a math book, but you will notice it is a straightforward review of the Ideal Gas Law. Memorize the conditions for STP, and spend a few minutes studying Figure 10.13 and the paragraph directly below it. || 10.25, 10.27, 10.33, and 10.36 page 400 ||
 * IV. || 10.5 || One important application of the ideal gas law involves density, as you may recall from last spring. Density is easily measured in a laboratory, and it can be used to determine the molar mass of a gas. Chemists use every type of experiment possible to determine molar mass since that number is perhaps the most important physical property of a substance. Study the sample exercises in this section and then pay special attention to problem 10.43, || 10.37, 10.39, 10.41, 10.43, and 10.45 page 401 ||
 * V. || 10.6 || A second important application of the ideal gas law involves mixtures of gases. The partial pressure of one gas in a mixture is a fairly easy concept to understand. In the lab, gases are often collected over water, as we did last year when we made hydrogen gas from Mg and HCl in a gas-collecting tube. Review page 385 carefully. Also, note that problems 10.51 and 10.88 are "classic" gas mixture questions. || 10.49, 10.51, 10.53, 10.55, 10.88, 10.90, 10.92, 10.105 pages 401-405 ||
 * VI. || 10.7 & 10.8 || These two sections can be considered one of the "chemistry essays" that you should re-read in April. They present a very organized overview of kinetic molecular theory. They also review one of the top ten important graphs in chemistry, which is shown in firgures 10.18 and 10.19. Two vocabulary terms are presented here: RMS speed and effusion. Both are worth understanding. Effusion is one more characteristic of a gas that can be used to nail down that most important physical property of a substance - molar mass. Note equation 10.24 (page 391) and problem 10.72. || 10.61, 10.65, 10.69, 10.72, and 10.81 pages 402-403 ||
 * VII. || 10.9 || The remarkably accurate ideal gas law and Kinetic Molecular Theory fail to predict gas behavior perfectly under two extreme conditions: high pressure and low temperature. The reasons for this deviation from reality are fairly easy to understand. They are summarized in this section of the chapter and corrected by equation 10.26 on page 395. For chemists, this is when things get really interesting; it's always the rule breakers that get our attention. For that reason, it is worth studying table 10.3. Look at xenon as one example. This single atom is so much bigger and more polarizable than carbon dioxide, and the data in table 10.3 make that clear for us. || 10.76, 10.77, 10.79, and 10.98 pages 403-404 ||

The reward(and punishment) for your efforts is shown below. You will be able to earn extra points on your next AP chemistry test. The number of points you earn depends on how many review sections you complete and the date of completion. In order to receive the points for a complete section, you must be able to show Mr. Robinson all the work for all of the problems in that section. There are a total of 30 problems in this assignment.


 * ~ Number of Review Sections completed ||||||~ Completion Date ||
 * || Tue, 1/10 || Fri, 1/13 || Mon, 1/16 ||
 * All seven ||= 4 ||= 3 ||= 2 ||
 * any five sections ||= 2 ||= 2 ||= 1 ||
 * any three sections ||= 1 ||= 0 ||= 0 ||

Never allow a table to be the last item on a wiki page. It messes up all the formatting.