Charles's law

In thermodynamics and physical chemistry, Charles's law is a gas law and specific instance of the ideal gas law, which states that:

At constant pressure, the volume of a given mass of an ideal gas increases or decreases by the same factor as its temperature (in Kelvin) increases or decreases.

The law was first published by Joseph Louis Gay-Lussac in 1802, but he referenced unpublished work by Jacques Charles from around 1787. This reference has led to the law being attributed to Charles. The relationship had been anticipated by the work of Guillaume Amontons in 1702. Charles's Law, Boyle's law, and Gay-Lussac'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.

Derivation

The formula for the law is:

Failed to parse (Missing texvc executable; please see math/README to configure.): \frac{V}{T} = k

where:

V is the volume of the gas

T is the temperature of the gas (measured in Kelvin)

k is a constant.

In other more thermodynamics-based definitions, the relationship between the fixed mass of a gas at constant pressure is inversely proportional to the temperature applied to the system, which can be further used by stipulating a system where Failed to parse (Missing texvc executable; please see math/README to configure.): \alpha

represents cubic expansivity of a gas, with Failed to parse (Missing texvc executable; please see math/README to configure.): \theta
representing the temperature measured of the system in Kelvins:

Failed to parse (Missing texvc executable; please see math/README to configure.): V \varpropto T

Failed to parse (Missing texvc executable; please see math/README to configure.): V = V_o(1 + \alpha\theta)

To maintain the constant, k, during heating of a gas at fixed pressure, the volume must increase. Conversely, cooling the gas decreases the volume. The exact value of the constant need not be known to make use of the law in comparison between two volumes of gas at equal pressure:

Failed to parse (Missing texvc executable; please see math/README to configure.): \frac{V_1}{T_1} = \frac{V_2}{T_2} \qquad \mathrm{or} \qquad \frac {V_2}{V_1} = \frac{T_2}{T_1} \qquad \mathrm{or} \qquad V_1\cdot T_2 = V_2\cdot T_1

.

Therefore, as temperature increases, the volume of the gas increases.

Theoretically as a gas reaches absolute zero the volume will also reach a point of zero.

This law is an example of direct variation

See also

Wikibooks School science has a page on the topic of

Making Charles' law tubes

• Boyle's law
• Gay-Lussac's law
• Ideal gas lawca:Llei de Charles i Gay-Lussac

id:Hukum Charles cs:Charlesův zákon el:Νόμος του Σαρλ es:Ley de Charles y Gay-Lussac fr:Loi de Gay-Lussac ga:Dlí de Charles gd:Dlighe de Charles hr:Charlesov zakon ko:샤를의 법칙 he:חוק שארל hu:Charles-törvény mk:Шарлов закон nl:Wet van Charles ja:シャルルの法則 pl:Prawo Gay-Lussaca (gaz doskonały) sl:Gay-Lussacov zakon fi:Charlesin laki vi:Định luật Gay-Lussac tr:Charles yasası