Gay-Lussac's Law Encyclopedia Article

Gay-Lussac's Law

The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.

(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.

The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.

The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.

All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.

Gay-Lussac's Law

By the late 1600s, scientists had learned that heat would make gases expand in volume, and British chemist Robert Boyle had begun to explain the relationship between the volume, pressure, and temperature of gases. He summarized his ideas in an expression, known as which states that the volume of a given amount of a gas varies inversely with pressure. This principle is important since chemistry often involves the study of gases that are hard to measure because they expand to fill whatever container they are in. The value of Boyle's law lies in its ability to calculate a gas's volume at a standard pressure without actually having to measure the volume at that pressure.

It was more than a century later, however, until a French chemist Joseph Gay-Lussac discovered, with a series of careful experiments, that different gases all expand in volume by the same amount with the same rise in temperature. Although he was the first to announce this principle in 1802, today it is more commonly known as Charles' law after French chemist Jacques Charles, who actually had the same idea earlier but did not publish his findings before Gay-Lussac.

Further, Gay-Lussac found that gases combine with each other in simple proportions--for example, two parts of hydrogen by volume reacts with one part oxygen to form water. This important elaboration came to be known as Gay-Lussac's law of combining volumes. These fundamental concepts were crucial to Amedeo Avogadro's discovery a few years later that equal volumes of gases at the same temperature and pressure contain the same number of molecules. Although Gay-Lussac's laws strictly apply only to certain theoretical gases (called "ideal"), many simple substances that are gases at room temperature and normal air pressure do behave as if they were ideal gases. Thus, the laws have proved extremely useful in explaining the behavior of gases, and they are considered fundamental concepts in chemistry and physics.