AP Chemistry

Electron Config

Electron Config

The atoms orbital config

Chemistry

study of what is in stuff reacting with other stuff

Matter

The stuff

Elements

pure substances that is a single element

Compounds

pure substances that is two or more element

Homogeneous

evenly distributed different mixture

Heterogeneous

chemically bonded elements not evenly distributed

protons or atomic number

How does the periodic table distribute its elements

P+>e-

cation

P+<e-

anion

isotopes

difference of neutrons in the same elements

What is most helpful when determining if a substance is pure?

Mass percent of the element

avagadro's number

6.022x10²³=1mole

mass spectrometry

A bar graph showing the different isotopes of an element. The total equals the element on the periodic table.

percent composition

summing atoms weight and dividing each individual by the sum.

empirical formula

Finding the ratio of atoms by making percents to equal grams by 100%=100g then turn to moles by timing m/g then dividing by the lowest atom and rounding others to nearest atom

molecular formula

the actual composition of a compound by taking empirical formula with actual mass

sig figs

The number of numbers that are relevant for a solution. (no leading zeros, sandwiched zeros are sig, yes trailing zeros if zero, yes none zeros)

proton

+in the nucleus with a weight of 1.00727

neutron

0in the nucleus with a weight of 1.00866

electron

-in the ion cloud with a weight of .00055

coulombs law (q=attraction)(r=distance)

(q_1q_2)/r^2

S config

first config of a layer a circle 2

P config

starts 2nd layer and second config of the layer a figure eight 3

D config

third level of atom a d shape 2

F config

last level of atom a shape

photoelectron spectroscopy

peaks showing the number of electrons from shells and energy use

Ionization energy (IE)

energy to remove an electron the (increase right and up)

electronegativity

ability to attract electrons ( increase right and up)

atomic radius/ radii

The distance of an electron from the nucleus (increase left and down)

ionic bond

metal and a nonmetal strongest bond ∆en 1.7-4.0

covalent bond

2 non metals

metalic

2 metals

hun's law

if atoms can fill out they would

polar covalent

∆en.3-1.7

non polar covalent

∆En0-.3

intra molecular forces

forces that impact bonding

perfect bond length

attractive forces = repulsive forces

determining strength of bonds

1 coulomb's law, 2 bond energy, 3 bond length, 4 atom size, 5 # of bonds

coulomb's law

(q1*q2)/r^2

bond energy

Kj of energy (higher = harder)

bond length

distance of atoms (closer=harder)

atom size

size of atom (smaller=harder)

# of bonds

1-3 bonds of an atom (more=harder)

crystal lattice

alternating repeating atoms that are ionic

metal

sea of electrons (made of same element)

alloy

substitutional and interstitial (made of a mix of metals)

substitutional

Two compound of relatively similar size switch atoms.

interstitial

Two compound of different sizes combine between bigger atoms.

formal charge (FC)

V-NB-b/2=FC determines which element is more neutral. (valence, non-bonding, bond e-,)

VESPR

used to determine 3d aspects of an atom (valence, shell, electron, pair, repulsion)

2 domains

linear sp 180˚

3 domain

trigonal planar 120˚ or lp bent <120

4 domain

trigonal planar 109.5˚, or lp trigonal pyramid <109.5 and 2 lp bent 90, 120˚

resonance structures

structures that can change orientation while being the same compound. Usually carbon and is due to equal lengths.

intramolecular forces

attractions within molecules

polarity of intermolecular forces

The high difference in electronegativity for covalent and ionic compounds (ionic always)

dipole

the attractions of a positive and negative polarity (greater difference = stronger dispersion forces)

London dispersion forces (LDF)

In temporary fluctuating dipoles, electrons are unevenly distributed to one side. (Changes are dependent on temp decrease = greater IMF)

dipole-dipole

attractions between oppositely charged regions of polar molecules

dipole-induced dipole

The partial charge on a polar molecule induces a temporary partial charge on a neighboring non polar molecule or atom

ion-dipole

the charge of an ion is attracted to the partial charge on a polar molecule.

hydrogen bonding

strongest of the bonds (hydrogen is always positive)(N, O, F)

Increasing IMF

Closer contact by greater size or bigger charge difference.

Effects of greater IMF

greater Breaking point, higher melting point, greater surface tension, lower vapor pressure.

Vapor pressure

The amount of free floating atoms based on temp.

pv=nRt

Pressure x Volume = # of moles x Gas Constant x Temperature

Pressure (P)

Measured in atmospheres STP 1 (KPA .00987 = atm 1)

volume (L)

Measured in Liters (L) STP 22.4

moles (n)

6.023*10^23 represented by mol The number of atoms present.

constant (R)

.08206 atm

temperature (T)

Measured in kelvin (K) average speed of atoms. (atoms can be going different speed)

boil's law

as P increases V decrease pv=pv

Charles' law

as v increase T increases. v/t=v/t

Gay-Lussac's Law

as P increase T increases. p/t=p/t

Avagadro's Law

as V/n = constant

Dalton's law

total pressure= p1+p2+p3+...

Assumptions of Kinetic molecular theory

gas particles have "no" volume

gas particle feel no attractions

constant motion

Kinetic energy (Ke)

Speed of atoms

mass

weight of an atom (different element and isotopes)

velocity (Ve)

energy an atom contains. (temp changes)

Ke= 1/2m*Ve^2

Mass decreases speed more velocity (increases by heat) making the atom go faster.

Grahm's Law of Effusion

smaller things diffuse faster out of membranes.

molar mass (MM)

grams / mol

ideal gas deviations

an increase in deviation. Less volume(L) lowers pressure, bigger molecules (MM) higher pressure.

ideal gas deviations

an increase in deviation. Low Temp, High IMF both decrease pressure

molarity (M)

mol/L

concentration

molarity is one way to calculate concentration (some #/ L)

Miscible

completely soluble

Imiscible

not fully soluble (ratios)

solvation

break solute-solute and solvent-solvent interactions forming solute-solvent interaction

exo

release energy

endo

take in energy

chromatography

separates two liquids with different polarity with paper and a liquid being polar (polar paper, higher is less polar)(nonpolar, higher is polar)

filtration

The separation of a liquid and a solid through a medium.

distillation

separating a liquid and liquid through evaporating (the end liquid is the distillate)

larger molecules

larger = more polarizable, high IMF, higher Bp (c-c-c-c) smaller than (c-c-c-c-c)

limits of models

Must assume some simplifications of complex issues. Some boundaries or limits identify. Not applicable to all situations.