1 historical synthesis
1.1 boyle s law
1.2 charles s law
1.3 gay-lussac s law
1.4 avogadro s law
1.5 dalton s law
historical synthesis
boyle s law
boyle s equipment.
boyle s law perhaps first expression of equation of state. in 1662 robert boyle performed series of experiments employing j-shaped glass tube, sealed on 1 end. mercury added tube, trapping fixed quantity of air in short, sealed end of tube. volume of gas measured additional mercury added tube. pressure of gas determined difference between mercury level in short end of tube , in long, open end. image of boyle s equipment shows of exotic tools used boyle during study of gases.
through these experiments, boyle noted pressure exerted gas held @ constant temperature varies inversely volume of gas. example, if volume halved, pressure doubled; , if volume doubled, pressure halved. given inverse relationship between pressure , volume, product of pressure (p) , volume (v) constant (k) given mass of confined gas long temperature constant. stated formula, is:
p
v
=
k
{\displaystyle pv=k}
because before , after volumes , pressures of fixed amount of gas, before , after temperatures same both equal constant k, can related equation:
p
1
v
1
=
p
2
v
2
.
{\displaystyle \qquad p_{1}v_{1}=p_{2}v_{2}.}
charles s law
in 1787, french physicist , balloon pioneer, jacques charles, found oxygen, nitrogen, hydrogen, carbon dioxide, , air expand same extent on same 80 kelvin interval. noted that, ideal gas @ constant pressure, volume directly proportional temperature:
v
1
t
1
=
v
2
t
2
{\displaystyle {\frac {v_{1}}{t_{1}}}={\frac {v_{2}}{t_{2}}}}
gay-lussac s law
in 1802, joseph louis gay-lussac published results of similar, though more extensive experiments. gay-lussac credited charle s earlier work naming law in honor. gay-lussac himself credited law describing pressure, found in 1809. states pressure exerted on container s sides ideal gas proportional temperature.
p
1
t
1
=
p
2
t
2
{\displaystyle {\frac {p_{1}}{t_{1}}}={\frac {p_{2}}{t_{2}}}\,}
avogadro s law
in 1811, amedeo avogadro verified equal volumes of pure gases contain same number of particles. theory not accepted until 1858 when italian chemist stanislao cannizzaro able explain non-ideal exceptions. work gases century prior, number bears name avogadro s constant represents number of atoms found in 12 grams of elemental carbon-12 (6.022×10 mol). specific number of gas particles, @ standard temperature , pressure (ideal gas law) occupies 22.40 liters, referred molar volume.
avogadro s law states volume occupied ideal gas proportional number of moles (or molecules) present in container. gives rise molar volume of gas, @ stp 22.4 dm (or litres). relation given by
v
1
n
1
=
v
2
n
2
{\displaystyle {\frac {v_{1}}{n_{1}}}={\frac {v_{2}}{n_{2}}}\,}
where n equal number of moles of gas (the number of molecules divided avogadro s number).
dalton s law
dalton s notation.
in 1801, john dalton published law of partial pressures work ideal gas law relationship: pressure of mixture of non reactive gases equal sum of pressures of of constituent gases alone. mathematically, can represented n species as:
pressuretotal = pressure1 + pressure2 + ... + pressuren
the image of dalton s journal depicts symbology used shorthand record path followed. among key journal observations upon mixing unreactive elastic fluids (gases) following:
unlike liquids, heavier gases did not drift bottom upon mixing.
gas particle identity played no role in determining final pressure (they behaved if size negligible).
^ mcpherson, pp.52–55
^ mcpherson, pp.55–60
^ john p. millington (1906). john dalton. pp. 72, 77–78.
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