## questionnn

why does an ideal gas change in temperature?? please be detailed
also what is the significance of 22.4? please be detailed

thank you very much

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22.4 what? 22.4 elephants?

why does anything change in temperature? because it gains or loses heat energy!

:? your questions are a little strange...

1 mole of ideal gas occupies 24.4dm³ [b]at room temperature and pressure[/b]

[quote="feline1"]22.4 what? 22.4 elephants?

why does anything change in temperature? because it gains or loses heat energy!

:? your questions are a little strange...[/quote]

Actually, they sound like essay questions for a take-home assignment to me. :roll:

[color=darkgreen]At STP (standard temperature and pressure) 1 mol of any ideal gas will occupy 22.4 liters of space. It comes from plugging the values into the ideal gas law equation, PV=nRT.[/color]

Avogadro's hypothesis actually is that at the same pressure and temperature equal volumes of gasses contain equal numbers of particles; therefore any volume could have been selected as the unit. The real question is therefore, is why was so odd a figure as 22.4 L chosen in the first place? Why not something round like 1 L, 10 L, 25 L or 100 L, why 22.4?

[quote="Martin17"]Avogadro's hypothesis actually is that at the same pressure and temperature equal volumes of gasses contain equal numbers of particles; therefore any volume could have been selected as the unit. The real question is therefore, is why was so odd a figure as 22.4 L chosen in the first place? Why not something round like 1 L, 10 L, 25 L or 100 L, why 22.4?[/quote]
Because if you wanted to use a rule that has a volume of say 10dm³, you would have to have a non-standard and hard-to-remember amount of gas, temperature or perssure. 1 Mole at STP (I mistakenly said RTP earlier, but that only gives an error of 0.1dm³) is far easier to remember.

That said, the TRUE volume at TRUE (IUPAC) STP is 22.7dm³ (Standard perssure, according to them, is 100kPa, not 101.325kPa)

PV=nRT was Avogadro? Funny, i thought some German guy discovered that.

PV=nRt is the gas law, it combines Charles' Law, P= C/V volume of a gas is inversely proportional to the pressure,(after Jacques-Alexandre Cesar Charles, a Frenchman, who noted the relationship in 1787 although it was rigorously formulated by Joseph-Louis Gay-Lussac in 1802, but he's also French so it doesn't really matter) and Boyle's Law P= KT, the pressure of a gas is directly proportional to the temperature (after Robert Boyle, an Englishman who proclaimed it in 1662); Gay-Lussac is also credited with a law, that volumes of gasses always react to one another in whole number ratios presented in 1808. Amadeo Avogadro (an Italian) was able to explain Gay-Lussac's law by positing that equal volumes of gasses contained equal numbers of particles in 1811 but he was ignored until 1858 when Stanislao Cannizzaro built something like our modern theory around the idea. You will note there are no Germans here. They didn't get involved until things got explosive. :)

WebElements: the periodic table on the WWW [http://www.webelements.com/]