Gay-Lussac's law

From Wikipedia, the free encyclopedia

You have new messages (last change).

Gay-Lussac's law, also known as the law of combining volumes, was named after the French chemist Joseph Louis Gay-Lussac. There are two laws that are attributed to Gay-Lussac which relate to the properties of gases, and are known by the same name.

Gay-Lussac's law states that the ratio between the combining volumes of gases and the product, if gaseous, can be expressed in small whole numbers, which Gay-Lussac discovered in 1809. In 1811, Avogadro used Gay-Lussac's data to form Avogadro's hypothesis which later gave way to modern gas stoichiometry.

The other law, discovered in 1802, states that the pressure of a fixed amount of gas at fixed volume is directly proportional to its temperature in kelvins. It is expressed mathematically as:

\frac{P}{T}=k

-Where:

This law holds true because temperature is a measure of the average kinetic energy of a substance; as the kinetic energy of a gas increases, its particles collide with the container walls more rapidly, thereby exerting increased pressure.

For comparing the same substance under two different sets of conditions, the law can be written as:

\frac{P_1}{T_1}=\frac{P_2}{T_2} \qquad \mathrm{or} \qquad {P_1}{T_2}={P_2}{T_1}

Charles's Law was also known as the Law of Charles and Gay-Lussac, because Charles used some of Gay-Lussac's data to formulate his law. However, in recent years the term has fallen out of favor since Gay-Lussac has the second but related law presented here attributed to him. This related form of Gay-Lussac's Law, Charles's Law, and Boyle's law form the combined gas law. The three gas laws in combination with Avogadro's Law can be generalized by the ideal gas law.

[edit] References

  • Castka, Joseph F.; Metcalfe, H. Clark; Davis, Raymond E.; Williams, John E. (2002). Modern Chemistry. Holt, Rinehart and Winston. ISBN 0-03-056537-5.
  • Guch, Ian (2003). The Complete Idiot's Guide to Chemistry. Alpha, Penguin Group Inc.. ISBN 1-59257-101-8.
  • Mascetta, Joseph A. (1998). How to Prepare for the SAT II Chemistry. Barron's. ISBN 0-7641-0331-8.
Retrieved from "http://en.wikipedia.org../../../g/a/y/Gay-Lussac%27s_law_009d.html"