ochem final

functional groups react

characteristically

skeleton structure

what percent of chem compounds have C

90

C valence and bonds

4 e-

4

diameter of atom

2 x 10 ^10

atomic number

number protons

mass number

number prot and neutrons

isotopes

Atoms of the same element that have different numbers of neutrons

atomic mass/weight

the weighted average of the masses of the isotopes of an element

takes abundance into account

quantum mechanics

describes e- energies and locations by wave equation

wave equation

generates function

each is an orbital (trident)

how to describe where e- most likely be

plot of orbitals

does e- cloud have boundary

no, so show most probably area

C only uses

s and p orbitals

s

spherical

p

dumbell, nuc at middle

d

4 lobes, 2 sets of p

lobe

bubble of orbital

separated by node

node

area of zero e- density

low prob of having them there

in each shell

3 perpendicular p orbitals

ground state electron configuration

the lowest energy arrangement of the electrons for each element

rules for gs config

1. lowest fill first

2. pauli exclusion principle

3. hund's rule

4s slightly lower energy than

3d

Pauli Exclusion Principle

Electrons in the same orbital must have opposite spin

hund's rule

electrons occupy orbitals of the same energy in a way that makes the number of electrons with the same spin direction as large as possible

how many bonds does c always have

4

ionic bond

transfer

salts

lewis structure

kekule structure

stable molecule

octet, or 2 for H

how to find number of bonds

8-group #

one atom's orbital overlaps another singly occ orb in a

cov bond

valence bond theory

e- are paired in overlapping orbitals and are attached to nuclei of both atoms

sigma

head on overlap

pi

side to side overlap

which type does every bond have

1 sigma

bond energy

energy released to form or absorbed to break bond

bond length

distance between nuclei that leads to max stability

if too close

repel

if too far

bonding is weak

max satbility

optimum distance between nuclei

hybridization vs groups of bond

1 - s

2 - sp

3 - sp2

4 - sp3

sp3 bond angle

109.5

sp3 shape

tetrahedral

4 unsymmetrical orbitals

bond length c-h

109pm (can change)

how to make sp3 orbital

one e- promoted to 2 p from 2s

correlation between bond length and strength

longer = weaker

sp2 angle

120

sp2 shape

trigonal planar

one p remainds unhybridized perpendicular to plane

how to make sp2

same as sp3, but C decides to do 3 bond groups

sp formation

same as sp3, but C chooses 2 to hybridize

sp angle

180

sp shape

Linear

2 p orbital unchanged on y and z axis perpencdicular to each other

acetylene is highly

flammable

electronegativity

the ability of an atom to attract electrons when the atom is in a cov bond

differences in En produce

bond polarity

most en

least en

fluorine

cesium

ionic character inc as

polarity inc

nonpolar covalent

EN is =

example of relatively nonpolar

c-h

polar covalent

partial neg and pos

different EN

key for functional groups

polar covalent bonds

ionic

diff EN >2

inductive effect

shifting of electrons in a bond in response to EN of nearby atoms

electrostatic potential maps

show e- dist with color

e- rich

red

e- poor

blue

bronsted lowry acid

donates a hydrogen cation

bronsted lowry base

acdepts h+

acidity constant

measures strength of acid

smaller pka =

stronger acid

ka =

[H+][A-]/[HA]

(products/reactants)

ph =

-log[pka]

water pka

15.7

stronger acid conjugate to

weaker base

stronger base holds

protons more tightly

if strong then _______ and weak then ____

strong-strong

weak-weak

organic acid

presence of polarized H atom

organic acid can cause

inductive effect

resonance structure

molecule trying to stabilize itself

organic base

atom with lone pair