Gay-Lussac’s law of combining

In order to work out reacting volumes of gases, we can use Gay-Lussac s law of combining volumes When gases react they do so in volumes which bear a simple ratio to each other and to the volumes of the products if they are gases, all measurements of volume being at the same temperature and pressure . 

Boyle (1662) observed that at constant temperature the volume of a sample of gas varies inversely with pressme, but Boyle did not explain why this was so. Somewhat later. Charles (1787) refined the observation to the effect that the volume of any sample of a gas vanes directly with the absolute temperature provided thal the pressure is held constant. A few years later, Gay-Lussac (1808), in reporting the results of his experiments with reacting gases, observed that volumes of gases that are used or produced in a chemical reaction can be expressed in ratios of small whole numbers—a concept to become known as Gay-Lussac s law of combining volumes. It should be noted that tlie foregoing concepts proposed by Boyle, Charles, and Gay-Lussac were based upon experimental observations, not on theory. 

Historically, the observation that volumes of reacting gases always simplified to ratios of small, whole numbers is called Gay-Lussac s Law of Combining Volumes. In the preceding example, the volumes of NO to 02 to N02 fit the pattern of 2 1 2. This observation further strengthened Dalton s argument for an atomic theory of matter. 

Gay-Lussac s Law of Combining Volumes. The measurement of the volumes of gases which enter into chemical reaction led Gay-Lussac to perceive the existence of an extremely simple relationship which is known by the above title and which may be stated as follows The volumes of gases which react chemically are in the ratio of small whole numbers. Furthermore, if the products of the reaction are also gaseous their volumes are also in the relation of small whole numbers to each other and to the volumes of the original gases. 

You have already learned that the ideal gas law can be used to solve for different variables in several different types of situations. As you may recall, the term stoichiometry" refers to the relationship between the number of moles of the reactants and the number of moles of the products in a chemical reaction. In this section, you will learn how to use Gay-Lussac s law of combining volumes and the ideal gas law to solve stoichiometric problems that involve gases. 

At the beginning of this chapter, you were introduced to Gay-Lussac s law of combining volumes When gases react, the volumes of the reactants and the products, measured at equal temperatures and pressures, are always in whole number ratios. As well, you learned that the mole ratios from a chemical equation are the same as the ratios of the volumes of the gases. 

This information will help you with a certain type of gas stoichiometry problem. When a gas reacts to produce another gas, you can use Gay-Lussac s law of combining volumes to find the volumes of the gases. The following Sample Problem shows you how. 

O fii Gay-Lussac s law of combining volumes provides a short-cut for some gas calculations. What type of gas reaction lets you use this law ... 

Italian chemist and physicist Amadeo Avogadro (1776-1856) proposed a correct molecular explanation for Gay-Lussac s law of combining volumes. His work provided a simple way to determine atomic weights and molecular weights of gases. 

Subsequent research proved that Gay-Lussac s Law of Combining Volumes is not exact, but only an approximation,4 so that oxygen and hydrogen do not behave as perfect gases. For an accurate calculation of the relative values for the atomic weights of hydrogen and oxygen, it is therefore essential to know not only the relative densities of the... 

Gay-Lussac s law of combining volumes relates the volumes of gases involved in a reaction, all measured separately at the same temperature and pressure. The volume ratio under these conditions is equal to the mole ratio and, therefore, to the ratio of coefficients in the balanced chemical equation (Section 12.9). 

J. L. Gay-Lussac, Memoire sur la combinaison des substances gazeuses, les unes avec les autres, Memoires de la Societe d Arcueil 2, 1809, 207-234 translated in Foundations of the Molecular Theory, Alembic Club Reprints, no. 4 (Edinburgh, 1950), 8-24 M. P. Crosland, The Origins of Gay-Lussac s Law of Combining Volumes of Gases, Annals of Science 17, 1961, 1-26. 

Crosland, Maurice. The Origins of Gay-Lussac s Law of Combining Volumes of Gases. Annals of Science 17, 1961, 1-26. 

Describe the relationships between gas behavior and chemical formulas, such as those expressed by Graham s law of diffusion, Gay-Lussac s law of combining volumes, and Dalton s law of partial pressures. 

In 1808, Joseph Gay-Lussac made an important discovery if the pressure and temperature are kept constant, gases react in volume proportions that are whole numbers. This is called Gay-Lussac s law of combining volumes. 

Gay-Lussac s law of combining volumes can be used to deduce the chemical formula of a gas through observation of volume changes in a chemical reaction. 

Gay-Lussac s law of combining volumes of gases/ley de combinacion de los volumenes de los gases de Gay-Lussac... 

The question immediately arose Are particles of the elements the same as Dalton s atoms Avogadro believed that they were not rather, he proposed that elements could exist as diatomic molecules. Avogadro s hypothesis could explain Gay-Lussac s law of combining volumes (Fig. 1.7). Thus, the reactions we wrote out in words become... 

Volumes may be expressed in any units as long as the same unit is used for all. Gay-Lussac summarized several experimental observations on combining volumes of gases. The summary is known as Gay-Lussac s Law of Combining Volumes ... 

Gay-Lussac s Law of Combining Volumes At constant temperature and pressure, the volumes of reacting gases (and any gaseous products) can be expressed as ratios of small whole numbers. 

Berzelius then set about determining atomic weights with more sophistication than Dalton had been able to do. In this project, Berzelius made use of the findings of Dulong and Petit and of Mitscher-lich, as well as of Gay-Lussac s law of combining volumes. (He did not, however, use Avogadro s hypothesis.) Berzelius s first table of atomic weights, published in 1828, compares favorably, for all but two or three elements, with the accepted values of today. 

Early in the nineteenth century, Gay-Lussac studied the volume relationships of reacting gases. His results, published in 1809, were summarized in a statement known as Gay-Lussac s law of combining volumes ... 

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