Afreen asked in Science & MathematicsChemistry · 6 years ago

another name of gay lussac's law? ( chemistry)?

A. combining volumes

B. diffusion

C. combining pressure

D. constant volume

Update:

whats correct

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• Dr W
Lv 7
6 years ago

A is the correct answer !!!!... Gay Lussac's law is the "law of combining volumes."

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.. PV = nRT

rearranging it

.. PV/(nT) = R

and since R is a constant, you must agree that ALL PV/(nT) are equal.. and for a gas in 2 states

.. P1V1/(n1T1) = P2V2/(n2T2)

now if we start holding different things constant, they drop out

for example

.. if n1 = n2... i.e... moles is constant

.. then n drops out and P1V1/T1 = P2V2/T2

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these are the 15 permutations of that relationship with different variables held constant

zero variables held constant

(1).. [P1V1/(n1T1) = P2V2/(n2T2)]... nothing held constant.... not named

one variable constant

(2).. [V1/(n1T1) = V2/(n2T2)]... P held constant.... not named

(3).. [P1/(n1T1) = P2/(n2T2)]... V held constant.... not named

(4).. [P1V1/T1 = P2V2/T2]... ... n held constant.... "combined gas law"

(5).. [P1V1/n1 = P2V2/n2]... ... T held constant..... not named

two variables held constant

(6)... [n1T1 = n2T2]...... ... ..P & V held constant.... not named

(7)... [V1/T1 = V2/T2]... ... ..P & n held constant.... "Charles law"

(8)... [V1/n1 = V2/n2]... ... ..P & T held constant.... "Avogadro's law"

(9)... [P1/T1 = P2/T2]... ... ..V & n held constant.... .. erroneously called "Gay Lussac's law"

(10). [P1/n1 = P2/n2]... ... ..V & T held constant.... .not named

(11). [P1V1 = P2V2]... ... .., n & T held constant.... "Boyles law"

and of course the trivial ones with 3 variables held constant

(12). [T1 = T2]... ... .P &.V & n... held constant.... not named

(13). [n1 = n2]... ... .P &.V & T... held constant.... not named

(14). [V1 = V2]... ... .P &.n & T... held constant.... not named

(15). [P1 = P2]... ... .V &.n & T... held constant.... not named

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all of these are special cases of the ideal gas law.

now notice I wrote "erroneously called Gay Lussac's law"' for #9?.. that is because

.. (4), (7), (8) and (11)

are named based on the scientists who worked on them OR

they are named because they are the combination of several works.

What about (9)?.. Gay Lussac studied the combination of volumes of gases at constant pressure. Same as Charles. NOT the combination of gases at constant volumes. That was the work of Guillaume Amontons in the year 1701 (77 years before Joseph Louis Gay-Lussac was even born). Equation (9) should rightly be called "Amontons Law". But for some reason, SOME high school chemistry teachers have decided to erroneously and perpetually preach that (9) is "Gay Lussac's law". They are WRONG !!!!

Perhaps John Park (aka chemteam), who happens to be one of those "preachers" (see his website) could shed some light on why he thinks P1/T1 = P2/T2 should be called "Gay Lussac's law".

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furthermore, the TRUE Gay-Lussac's law should be

.. "the law of combining volumes"

Gay-Lussac discovered that

.. 1 volume of O2 + 2 volumes H2 --> 2 volumes H2O

• 6 years ago

Gay-Lussac's law is a constant volume process:

http://chemteam.info/GasLaw/Gas-Gay-Lussac.html