Created in the early 17th century, the gas laws have been around to assist scientists in finding volumes, amount, pressures and temperature when coming to matters of gas. The gas laws consist of three primary laws: Charles' Law, Boyle's Law and Avogadro's Law (all of which will later combine into the General Gas Equation and Ideal Gas Law).

An ideal gas is defined as one in which all collisions between atoms or molecules are perfectly elastic and in which there are no inter molecular attractive forces. One can visualize it as a collection of perfectly hard spheres which collide but which otherwise do not interact with each other. In such a gas, all the internal energy is in the form of kinetic energy and any change in internal energy is accompanied by a change in temperature.

  • n = number of moles

  • R = universal gas constant = 8.3145 J/mol K

  • N = number of molecules

  • k = Boltzmann constant = 1.38066 x 10-23 J/K = 8.617385 x 10-5 eV/K

  • k = R/NA

  • NA = Avogadro's number = 6.0221 x 1023 /mol

Combined and ideal gas laws: PV=nRT

P  is the absolute 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 temperature (K)

The three fundamental gas laws discover the relationship of pressure, temperature, volume and amount of gas. Boyle's Law tells us that the volume of gas increases as the pressure decreases. Charles' Law tells us that the volume of gas increases as the temperature increases. Avogadro's Law tell us that the volume of gas increases as the amount of gas increases. The ideal gas law is the combination of the three simple gas laws.

 

Other Gas Laws:

  • 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.
  • 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.
  • P_{total} = P_1 + P_2 + P_3 + ... + P_n \equiv \sum_{i=1}^n P_i \,,

    OR

    P_\mathrm{total} = P_\mathrm{gas} + P_\mathrm{H_2 O} \,

PV=kNT

P  is pressure

V  is volume

N is the number of moles

R  is the universal gas constant

T  is temperature (K)

Work Cited:

http://chemistry.bd.psu.edu/jircitano/gases.html

http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch4/  

http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/idegas.html

http://chemwiki.ucdavis.edu/Physical_Chemistry/Physical_Properties_of_Matter/Phases_of_Matter/Gases/Gas_Laws