Mariotte’s law

A perfect" gas is one which closely conforms id the simple gas laws" of expansion and contraction, such as Boyle s Law, formulated in England by The Hon Robert Boyle (1627-169D (Ref 1, p 141-R) and called in France Mariotte s Law, because it was formulated independently from Boyle by Edme Mariotte (1629-1684) (Ref 1, p 515-L). This law, called in Germany and Russia... 

Boyle-Mariotte s Law, states that the product of volume and pressure is constant, pv=k, at const temp. Another gas law states that the vol of a gas at 0°C increases with each °C by 1/273, provided the pressure is constant, and that the pressure increases with each °C, provided the volume remains constant. This law is known as Charles1 Law, because it was formulated by French chemist Jacques Charles (1746-1822) (Ref 1, p 186-R). The so-called Dalton s Law, formulated by John Dalton (1766—1844), Engl chemist physicist, founder of atomic theory, states that the pressure of a gas mixture equals the sum of the partial pressures of the constituent gases (Ref 1, p 252-R). The so-called Gay-Lussoc s Law states that when gases interact, the volumes of the reacting gases and the volume of the reaction product are in simple, proportions and can be expressed by whole numbers. This law was formulated by a French chemist and physicist Gay-Lussac(qv) Refs 1) Hackh s Diet (1944), pp 89-R, 141-R,... 

Edme Mariotte, a French scientist, investigated the pressure-volume relationship of gases independently of Boyle. He did not publish his work until 1676, fourteen years after Boyle had. In many European countries, the mathematical relationship between gas pressure and volume is known as Mariotte s Law. 

Suppose that the system is brought in the initial and final conditions to the same temperature we may make it pass from the first to the second without variation of temperature this third modification will differ, in general, from the two pi eding if the system is a gas that obeys Mariotte s Law, we may find the value of the work done during this last modification this value, given by equation (11), will differ again from the two preceding. 

Gases which obey Mariotte s Law. Absolute temperature.— Before applying the principle of the equivalence of heat and work to the various problems of chemical calorimetry, we shall make an application which we shall employ in what follows. 

All are acquainted with the statement of Mariotte s Law at a given temperature, the product of the pressure supported by a mass of gas and the volume it occupies is a constant. Everybody knows also lhat this law does not apply rigorously to any gas, but that the gases distant from the conditions in which they liquify obey this law approximately. 

It results from this law, as is taught in elementary classes, that the two coefficients of expansion, under constant pressure and constant volume, of a gas obeying this law have the same value, and this with whatever thermometer used besides, according to the observations of Charles and of Gay-Lussac, this value is the same for all gases which follow sensibly Mariotte s Law finally, if the thermometer chosen is one constructed with one of these gases, the value in question evidently does not depend upon the temperature. 

If the temperature chosen is a centigrade temperature, the coefficient of expansion of gases which obey Mariotte s Law is sensibly, according to Regnatilt s observations, a= f+y. 

B aniiMi a gas In vacuo. Gay-Lussac erimcnt —The gases which obey Mariotte s Law approximately, obey also, approxiinate y, another law illustrated by an old experiment of Oay-Lusssc, repeated ty B uault, by W. Thomson, and by Joule. Two reservoirs B, (Fig. 17), one of volume v, the otiitf ef... 

Applicfttion to ft gas that obeys Mariotte s law, 11.—8. In some cases, the work of the forces applied to a system depends only on the initial and final states of this system, 12.—. In general, the work done by the forces applied to a system depends upon every modification the system undergoes, 12.—10. Potential, 14.—11. Potential due to gravity, 16.—la. Forces which admit a potential in virtue of the restrictions imposed upon the system, 16.—13. Energy, 16.—14. Principle of virtual displacements, 17.—15. Conservatives of energy. Conservative systems, 18.—16. Principle of virtual displacements for conservative systems. Stability of equilibrium, 19. 

In atomic structure there exists a kind of Mariotte s law the power 3/2 of the electric potential playing here the role of pressure. 

Or Mariotte s law, as they say in France. The Frenchman E. Mariotte discovered the same relation, independently of Boyle, and even noted that it was only valid if the temperature remained constant. 

Boyle-Mariotte s Law Robert Boyle investigated the pressure dependent changes in the volume of gases when temperature is kept constant. We want to model this investigation using a demonstration experiment (Experiment 10.1). 

In 1664 and 1676, Robert Boyle and Edme Mariotte, independently found (and also we found in our experiment) The volume of a given amount of gas at constant temperature is inversely proportional to its pressure (Boyle-Mariotte s law) ... 

Experiment 10.1 Boyle-Mariotte s law Starting with the lowest weight, different weights are placed successively upon a piston of a cylinder made of acrylic glass. If the cross section of the piston equals 1.8 cm the pressure increases a factor of 2,4, 10 due to the weights stacked upon each other, and the volume decreases to... 

Fig. 10.1 Isotherms of a gas obeying Boyle-Mariotte s law, for two different temperatures (Ti>To).

Boylo s law The volume (V) of a given mass of gas at a constant temperature is inversely proportional to its pressure (p), i.e. pV= constant. This is true only for an "ideal gas. This law was discovered in 1662 by Robert Boyle. On the continent of Europe it is known as Mariotte s law after E. Marlotte (1620-84), who discovered it Independently in 1676. See also gas laws. 

Edme Mariotte (1620-1684), a French physicist and priest, discovered Boyle s law independently of Boyle in 1676, so the law is also known as Boyle-Mariotte s law. In 1660, Mariotte also discovered the eye s blind spot. He worked on many subjects, such as the motion of fluids, the nature of color, the notes of the trumpet, the barometer, the fall of bodies, and the freezing of water. 

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