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OAT - Chem
Chapter 7- The Gas Phase
Term | Definition |
---|---|
The phases/states | solid, liquid, gas |
Gases | molecules move rapidly, are far apart, can expand to fill any volume, take the shape of a container, and are compressible |
What variables help define gases | P, V, T, n |
(STP) P (pressure) | 1 atm = 760 torr = 760 mm Hg |
V (volume) | mL or L |
(STP) T (temperature) | 273 K |
STP | standard temp and pressure = 1 atm and 273K; V = 22.4L, n = 1mole |
Standard Conditions | 298K, enthalpy, entropy, Gibbs, voltage |
Ideal Gases | a hypothetical gas whose molecules have no intermolecular forces and occupy no volume; high temp, low P |
Boyle's Law | Under isothermal conditions, P1V1 = P2V2 |
Charles' Law | under constant pressure conditions, V1/T1 = V2/T2 |
n | number of moles |
Avogadro's Principle | when pressure and temp are constant, n1/V1 = n2/V2 |
Ideal Gas Law | PV = nRT |
R | gas constant; = 8.21E-2; 8.314J/Kmol |
Density | mass/volume; g/L for gases |
Deviations Due to Pressure | as P increases, gas condenses into liquid state |
Deviations Due to Temp | As T decreases, gas condenses into liquid state |
Dalton's Law of Partial Pressures | the total pressure of a gaseous mixture is equal to the sum of the partial pressures of the individual components; Ptot= P1 + P2 + etc |
P1 = Ptot (X1) | Partial pressure equation |
KE equation for gases | avg KE is proportional to absolute T; KE = 3/2 KT |
Graham's Law of Diffusion and Effusion Eq | r1/r2 = [MM2/MM1]^1/2 |