CHEM 14A Ch 4 10 16 Ideal Gases Chemic
Ideal gases:
No volume, no intermolecular forces
Atoms/Molecules that are gases at room temperature
Noble Gases. H2, N2, O2, F2, Cl2. Methane, ethane, propane, butane
Gas:
Fills the container. Forces of intermolecular attraction are weak.
Vapor:
Gas state of a substance that is usually a liquid or solid
Ek = (Kinetic energy of a gas molecule)
Mu2/2. U2 = 3 (R Gas Constant) (Temperature in Kelvin) / molar mass in kg
Speed goes
Up with temp and down with mass
Pressure:
Collisions with the side of a container (surface area)
Pressure formula:
F/A in Pascal (Pa)
760 mm Hg or: is equal to
760 Torr = 1 atm = 105 Pa /////// 1 bar = 0.98692 atm
Ideal Gas Law:
PV = nRT. Set certain variables equal to each other
Dalton’s Law of Partial Pressures:
Ptotal = P1 + P2 + …
Hot gases are
Less dense than cold gases because there are less molecules in the same volume
Density =
Mass / volume. Relate it to Ideal Gas Law.
Increasing pressure
Increasing density
Rxn reaches equilibrium when
Concentration of Reactant and Product does not change. The Reactants and Products are still forming.
Under same conditions, rxn at equilibrium has
Same ratio of products/reactants. Ratio is Equilibrium Constant, KC
KC =
[C]c[D]d/[A]a[B]b
Homogenous equilibria
Chemical equilibria w/ all R & P in same phase (gas, liquid, etc)
Heterogeneous equilibria – Pure substances are
Solids or liquids. Not included in equations
Range for K in favoring:
K > 103 favors formation of products. K < 10-3 favors reactants. Intermediate values (10-3 to 103) neither is favored.
Reaction quotient:
Q at any time during the reaction. Or QC or QP
If Q < K: If Q > K:
Products more favored. Reactants more favored.
Equilibrium Composition:
Finding the molar concentration/molarity of equilibrium of each molecule
ICE Box: middle box:
Adds/subtracts by multiples of X.
Le Chatelier’s principle
Chemical rxns adjust so as to minimize the effect of any changes. By P & T
Increasing pressure by decreasing volume
Depends on
No volume, no intermolecular forces
Atoms/Molecules that are gases at room temperature
Noble Gases. H2, N2, O2, F2, Cl2. Methane, ethane, propane, butane
Gas:
Fills the container. Forces of intermolecular attraction are weak.
Vapor:
Gas state of a substance that is usually a liquid or solid
Ek = (Kinetic energy of a gas molecule)
Mu2/2. U2 = 3 (R Gas Constant) (Temperature in Kelvin) / molar mass in kg
Speed goes
Up with temp and down with mass
Pressure:
Collisions with the side of a container (surface area)
Pressure formula:
F/A in Pascal (Pa)
760 mm Hg or: is equal to
760 Torr = 1 atm = 105 Pa /////// 1 bar = 0.98692 atm
Ideal Gas Law:
PV = nRT. Set certain variables equal to each other
Dalton’s Law of Partial Pressures:
Ptotal = P1 + P2 + …
Hot gases are
Less dense than cold gases because there are less molecules in the same volume
Density =
Mass / volume. Relate it to Ideal Gas Law.
Increasing pressure
Increasing density
Rxn reaches equilibrium when
Concentration of Reactant and Product does not change. The Reactants and Products are still forming.
Under same conditions, rxn at equilibrium has
Same ratio of products/reactants. Ratio is Equilibrium Constant, KC
KC =
[C]c[D]d/[A]a[B]b
Homogenous equilibria
Chemical equilibria w/ all R & P in same phase (gas, liquid, etc)
Heterogeneous equilibria – Pure substances are
Solids or liquids. Not included in equations
Range for K in favoring:
K > 103 favors formation of products. K < 10-3 favors reactants. Intermediate values (10-3 to 103) neither is favored.
Reaction quotient:
Q at any time during the reaction. Or QC or QP
If Q < K: If Q > K:
Products more favored. Reactants more favored.
Equilibrium Composition:
Finding the molar concentration/molarity of equilibrium of each molecule
ICE Box: middle box:
Adds/subtracts by multiples of X.
Le Chatelier’s principle
Chemical rxns adjust so as to minimize the effect of any changes. By P & T
Increasing pressure by decreasing volume
Depends on