AP Chem Review Sheet Test Chapters 6-9

AP Chemistry Test Chapters 6-9

Chapter 6- Gases

Equations:

Combined Gas Law	P1V1 = P2V2  T1        T2
Boyle’s Law	P1V1 = P2V2      PV=K
Charles’ Law	V1 = V2                   V = K T1    T2                    T
Gay Lusac’s Law	P1 = P2                   P = K T1    T2                    T
Ideal Gas Law	PV=nRT   R=.0821 liters atm                                    n Kelvin
Ideal Gas Law Variation	MW= wtRT       MW= DRT                         PV                       P
Dalton’s Law of Partial Pressure	Ptotal = P1 + P2…
Rault’s Law	Px = nxPT
Graham’s Law of Effusion	Rate1 = √MW2 = T2 Rate2    √MW1    T1
Corrected Ideal Gas Law/ Van Der Waals Equation	(P+n2a)(V-nb) = nRT        V2
Root Mean Square Speed	U2 = 3RT                      MW                                   R=8.31 x 107 g cm2                       s2 n K

Essay- KMT

Why was the ideal gas law revised?

The KMT was established to mathematically derive the gas laws.  Two of the theories 5 postulates, however, are false.  These false postulates state that gases have no volume and no attractive forces.  Under high pressure, a gas’ volume becomes significant, so gases do have volume.  We also know that there are intermolecular forces between gas molecules.  Since these two postulates were proven false, the ideal gas law had to be rewritten to work for all gases.  Attractive forces were added to the pressure to account for the attractive forces that exist between gases.  The volume of the gas is subtracted from the volume of the container to account for the volume of a gas.

Chapter 7- Electronic Structure

Equations:

Planck’s Constant	6.63 x 10-34 J sec                   Particle (photon)
Energy of Light (chemists)	E = 1.196 x 105   KJ            λ                  n
Energy of Light (physicists)	E = 1.986 x 10-25     J    .            λ                  particle
Energy of H2	E = -2.179 x 10-18    J   .                    n2              particle n=shell #
Energy of H2	E = -1312       KJ                        n2       mole n=shell #
DeBroglie Equation	λ = h                      mV              m= mass                         V= velocity               h= planck's constant

λ blue light = 400nm / 4000 Å

λ red light = 700nm/ 7000 Å

Quantized energy- energy absorbed when an electron jumps from the ground state to an excited state.  When the electron falls back down to the ground state, the quantized energy is emitted as light.

Hydrogen Spectra

Hund’s Rule of Maximum Multiplicity

-       Subshells which are ½ or completely filled have an enhanced stability

-       A shift of one electron from an s to a d or f orbital makes all shells ½ or completely filled

-       “Dental metals” are unreactive because of Hund’s rule (Cu, Ag, Au, Cr, Pt)

-       When you go across a period on the periodic table, the ionization energy does not increase smoothly because of Hund’s rule.

Chapter 8- Periodic Law

Ionization energy

-       Amount of energy required to remove and electron from an atom

-       As you go across a period, the Ie increases

-       As you go down a row, the Ie decreases

Electronegativity

-       Relative attraction for an electron

-       As you go across a period, the En increases

-       As you go down a row, the En decreases

Atomic radius

-       Distance from the nucleus to the outer shell

-       Decreases as you go across a period (more protons pulling electrons closer)

-       Increases as you go down a row (more shells)

Electron affinity

-       Amount of energy required for an atom to gain an electron

-       Reverse of Ie

Alloys

-       A material with metallic properties that contains two or more elements, at least one being a metal

-       Lower melting point

-       Increases the hardness

-       Lowers the electrical and thermal conductivity

Reactions with Hydrogen

-       Group 1 and 2 metals react with hydrogen at high temperatures to form ionic hydrides

-       Ionic hydrides contain H^- ions, and are often called saline hydrides

-       Saline hydrides react with water to produce hydrogen gas

Reactions with Water

-       Group 1 and 2 metals react with water to produce hydrogen gas, simultaneously creating a water solution of alkali hydroxide.  These reactions produce a lot of heat (big – ΔH)

Reactions with Oxygen

-       When oxygen reacts with metals from groups 1 and 2, three different oxides can form- oxide, peroxide, or superoxide

-       Oxides contain O^-2 and a metal ion

o   Group 1 oxide- M₂O (2 M⁺ ions and 1 O^-2 ion)

o   Group 2 oxide- MO (1 M⁺² ion and 1 O^-2 ion)

-       Peroxides contain O₂^-2 and produce hydrogen peroxide when added to water (most important are Na₂O₂ and BaO₂)

-       Superoxides contain O₂^- (most important is KO₂)