Gas Laws
Boyle\'s Law
Boyle\'s Law states that, at constant temperature, the product of the pressure and volume of a given mass of an ideal gas in a closed system is always constant.
It can be verified experimentally using a pressure gauge and a variable volume container. It can also be derived from the kinetic theory of gases: if a container, with a fixed number of molecules inside, is reduced in volume, more molecules will strike a given area of the sides of the container per unit time, causing a greater pressure.
As a mathematical equation, Boyle\'s Law is written as either:
P∝ 1/V
PV=K1
P1V1=P2V2
where P is the pressure, and V is the volume of a gas, and k1 is the constant in this equation (and is not the same as the proportionality constants in the other equations below). The statement of Boyle \'s law is as follows:
The volume of a given mass of a gas is inversely related to the pressure exerted on it at a given temperature and given number of moles.
Charles\' Law' Charles\' Law states that, for a given mass of an ideal gas at constant pressure, the volume is directly proportional to its absolute temperature, assuming in a closed system.
As a mathematical equation, Charles\' Law is written as either:
V ∝ T
V/T=K2
V1/T1 = V2/T2
where V is the volume of a gas, T is the absolute temperature and k2 is a proportionality constant
Gay-Lussac\'s Law Gay-Lussac\'s Law states that, for a given mass and constant volume of an ideal gas, the pressure exerted on the sides of its container is directly proportional to its absolute temperature.
As a mathematical equation, Gay-Lussac\'s Law is written as either
P ∝ T
P/T=K3
P1/T1 = P2/T2
where P is the pressure, T is the absolute temperature, and K3 is another proportionality constant
Avogadro\'s Law', 'avogadro-s-law', 'Avogadro\'s Law states that the volume occupied by an ideal gas is directly proportional to the number of molecules of the gas present in the container.
This gives rise to the molar volume of a gas, which at STP is 22.4 litres.
The relation is given by
V1/n1 = V2/n2
where n is equal to the number of molecules of gas (or the number of moles of gas.
Combined and Ideal Gas Laws The Combined Gas Law or General Gas Equation is obtained by combining the three preceding gas laws, and shows the relationship between the pressure, volume, and temperature for a fixed mass (quantity) of gas:
PV=K5T
This can also be written as:
P1V1/T1 = P2V2/T2
With the addition of Avogadro\'s Law, the combined gas law develops into the Ideal Gas Law:
PV = nRT
where
P is pressure
V is volume
n is the number of moles
R is the universal gas constant
T is temperature (K)
where the proportionality constant, now named R, is the universal gas constant with a value of 0.08206 (atm∙L)/(mol∙K). An equivalent formulation of this Law is:
PV=kNT
where
P is the pressure
V is the volume
N is the number of gas molecules
k is the Boltzmann constant (1.381×10−23 J•K−1 in SI units)
T is the absolute temperature
These equations are exact only for an ideal gas, which neglects various intermolecular effects. However, the ideal gas law is a good approximation for most gases under moderate pressure and temperature.
This law has the following important consequences:
1. If temperature and pressure are kept constant, then the volume of the gas is directly proportional to the number of molecules of gas.
2. If the temperature and volume remain constant, then the pressure of the gas changes is directly proportional to the number of molecules of gas present.
3. If the number of gas molecules and the temperature remain constant, then the pressure is inversely proportional to the volume.
4. If the temperature changes and the number of gas molecules are kept constant, then either pressure or volume (or both) will change in direct proportion to the temperature.
Graham\'s law Graham\'s law states that the rate at which gas molecules diffuse is inversely proportional to the square root of its density.
Combined with Avogadro\'s law (i.e. since equal volumes have equal number of molecules) this is the same as being inversely proportional to the root of the molecular weight.
', '', 1, 101, '2016-04-26 00:28:54', 94, '', '2016-04-26 00:28:54', 0, 0, '2016-05-20 07:16:42', '2016-04-26 00:28:54', ationrticle_options1, 3, '', '', 1, 527, (216, 375, 'Dalton\'s law', 'dalton-s-law', 'Dalton\'s law of partial pressures states that the pressure of a mixture of gases simply is the sum of the partial pressures of the individual components.
Dalton\'s Law is as follows:
PTotal = P1 + P2 + P3 + ... +Pn = ∑ Pi where i = 1 to n
OR
PTotal = PGas + PH2O
where PTotal is the total pressure of the atmosphere, PGas is the pressure of the gas mixture in the atmosphere, and PH2O is the water pressure at that temperature
Henry's law
Henry's law states that:
At constant temperature, the amount of a given gas dissolved in a given type and volume of liquid is directly proportional to the partial pressure (p)of that gas in equilibrium with that liquid.
p=kHc