VIEWS: 7 PAGES: 8 POSTED ON: 3/13/2012
Ideal Gas Equation/Molar & Molecular Mass Thermal Physics Lesson 4 Learning Objectives Define a mole Calculate the number of moles in a gas using N=nNA Perform calculations using the ideal gas equation pV=nRT Describe the conditions for which a real gas behaves like an ideal gas Avogadro’s Constant One mole of any gas contains the same number of particles. This number is called Avogadro’s constant and has the symbol NA. The value of NA is 6.02 × 1023 particles per mole. Calculating the Number of Moles The number of moles, n, of a gas can be can be calculated using:- N n NA Where N is the total number of molecules and NA is Avogadro’s constant (=6.02 × 1023) Avogadro’s Law The most significant consequence of Avogadro's law is that the ideal gas constant has the same value for all gases. This means that the constant is given by:- V n p1V1 p2V2 constant T1n1 T2 n2 Deriving Ideal Gas Equation 1 From Boyle’s Law: V p From Pressure Law: V T From Avogadro’s Law: V n Combining these three: nT V p Rewriting using the gas constant R: nT Therefore:- p V R pV nRT The Ideal Gas Equation Combining the three gas laws gives the equation:- pV constant The constant is equal to T nR. Works well for gases at low pressure and fairly pV nRT high temperatures Equation of State Recall that each phase can exist in a variety of states e.g. the temperature and pressure Thus the Ideal Gas Equation of State pV = nRT summarises the physically possible combinations of p, V and T for n moles of the ideal gas.
Pages to are hidden for
"Ideal Gas Equation.ppt - RanelaghALevelPhysics"Please download to view full document