chem 1a midterm 2

AX2E0

linear, 180

AX3E0

trigonal planar, 120

AX2E1

bent, <120

AX4E0

tetrahedral, 109.5

AX3E1

trigonal pyramidal, 109.5

AX2E2

bent, 109.5

AX5E0

trigonal bipyramidal, 90, 120

AX4E1

seesaw, 90, 120

AX3E2

T-shaped, 90

AX2E3

Linear, 180

AX6E0

octahedral, 90

AX5E1

square pyramidal, 90

AX4E2

square planar, 90

AX3E3

T-shaped, 90, 180

AX2E4

linear, 180

2 in electronic geometry

linear

3 in electronic geometry

trigonal planar

4 in electronic geometry

tetrahedral

5 in electronic geometry

trigonal bipyramidal

Pressure

Force/area

760 torr

1 atm

As volume increases

pressure decreases.

as temp increases

volume increases.

as moles increase

volume increases.

Ideal Gas Law

PV = nRT

Ideal Gas Conditions

Gas will be most ideal at low pressures and high temperatures.

Dalton's Law of Partial Pressures

Ptotal = P1 + P2 + P3 +…

Mole Fraction

X1 mole fraction = n1/ntotal = P1/Ptotal

Kinetic molecular theory

1) Gas molecules are small compared to space between them 2) Particles are in constant motion 3) Neither attract nor repel each other 4) Average kinetic energy: KEavg directly proportional to temp

Average kinetic energy formula

KEavg = 3/2 RT

Root mean squared velocity

√(3RT/M)

Average velocity formula

Mavg = √(8RT/M)

Boltzmann's constant

R/NA

Diffusion

Mixing of gases

Effusion

Gas passes through pinhole

Collision rate

Collisions per second = ZA

Real gases assumptions

1) Gas molecules have no volume 2) Gas molecules are not attracted to each other

Van der Waals equation

Spectroscopy

Analysis of electromagnetic radiation emitted or absorbed by substance

Frequency

Cycles/sec in 1/s or Hertz (Hz)

Wavelength and frequency relationship

Wavelength * frequency = c (speed of light)

Wavelength order

Red wavelength > green > blue

Energy formula

Energy = (h * c)/frequency

Planck's constant (h)

h = 6.626 x 10^-34 J*S

Photoelectric effect

Phenomenon where light can eject electrons from metals.

Kinetic energy of electron (KEe-)

KEe- = Ephoton - Binding

Kinetic energy formula

½ mev^2 = hfrequency - hfrequency0

De Broglie equation

Wavelength = h/mv

X-ray diffraction

Technique used to measure crystal layer spacings.

Constructive interference

Waves add together for increased intensity.

Destructive interference

Trough of one wave meets the peak of another, canceling out.

Emission spectrum

The spectrum of light emitted by a substance.

Bohr Model

Model of the atom with fixed energy levels.

Principal quantum number (n)

Indicates the energy level of an electron.

Ionization energy

Energy required to remove an electron.

Heisenberg uncertainty principle

Cannot simultaneously define position and momentum of an electron.

Orbital energy level order

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s

Electronegativity

Ability of an atom to attract electrons.

Ionic radius

Size of an ion compared to its neutral atom.

Lewis structures

Diagrams showing valence electrons in a molecule or ion.