Class notes
Chemistry 20 AP Notes
- Course
- Institution
Chemistry 20 AP notes including bonding, gases, solutions, and stoichiometry. Handwritten notes with diagrams and practice problems. Final class grade was 93%.
[Show more]
Seller
Follow
penelopefurtado12
Content preview
unit one; bondingHydrates 06 02 24
.
.
-
lonk compounds that have a certain number of water molecules in their formula
4) CuNO , · GH , O + copper (1) nexahydrate
4)
CasOe o
SH20 >
-
calcium sulfate pentahydrate
Atoms 12 02
.
.
24
-
atomic number is the number of protons in an atom
-
electrically neutral means protons (p+) =
electrons (e)
form compounds in an effort to complete valence shell (octet rule)
-
atoms gain a
Electron Dot Diagram
-
show only valence e, all other shells are full and don't participate in bonding
e ' individually
place for the first ? then pair up as each other and will remain alone if possible
necessary ; e- repel
-
-
bonding occurs with unpaired electrons
Forming Bonds
-
cations and anions form an lonk band I' are transferred to the anion resulting in an loni solid
, ,
-
typically two non-metals form a covalent wond , e are shared
-
bonds result from attraction of nucles for electrons (electroneganvin)
↳ e
9
Na ici
-
t
. .
- -
-
-
Cl .. > sodium chloride
-
Na ~
..
-
[ F )
"
:
... F :
-
,
:
-
ca +
ca] calcium fivoricle
-
> 7
3.
Fi 1 F ]
: :
+
(Mg)"
I
u9in :
"
( N ) : :
·
magnesium nitricle
lMg !
Mig .
( N )
: :
:
+
(Mg)"
"
Nig
lonk
Bonding and Crystal Lattices
-
once an 101 forms
,
each cation attracts any nearby anions
-
for NaCl each con attracts 6 long of opposite charge
,
4 all attractive forces are equal ,
so no specific pairs of sodium and chlorine could be labelled as a molecule
4 formula Nacl implies the 2 lons form a 3D crystal lattice with a 1 : 1 ratic
4 Nacl is a formula unit, not a molecule
-
strong attraction in 3D lattices is what makes all lonk compounds solids at room temperature
4 high melting point as lots of energy is required to overcome strong electrostatic forces
metal character
-
metals are good electrical conductors because electrons in the electron sea are free to flow and carry electrical current
-
malleable ductle because local bonds can easily be broken and reformed
,
-
group trend : as you go down a group metallic character
,
increases because lonization energy decreases
-
period trend : as you go across a period (L to R) metallic character decreases because lonization energy increases
Metallic Bonds
-
form between delocalized electrons and positively charged Metallic lons
-
metals do not form bonds with other metals because of surface roughness ,
the atoms cannot get physically close enough
·
covalent Bonds
Oxygen difluoride
non-conductors all phases ↑ F
typically involves 2 or more non metals ; low melting/boiling point soft solids in
-
,
,
-
Most common is single wond ,
sharing of 1 pair of electrons between atoms
-
usually molecule furthest to left is written first H -... H H
P""I phosphorus trimydride
H
it
, BondingTerminology
pairs : formed when there are more than he in the valence shell
electron dot
diagram -electron
-
unpaired electrons : electrons that don't have a partner ,
form bonds with other atoms
pair : When two atoms share electrons and form covalent bond
[-ounding
a
Molecules
-
lone pair : electron pairs not involved in ronding
single wond : I shared pair of electrons
-
bond types
" -
-
double bond
triple wond
:
:
2
3
shared pairs
shared pairs
of
of
electrons
electrons
4) Bond Type Example Diagranis
CO :O : C :: O : double wond
HCN H -
:
C N :
single bund triple bond ,
Structural Formulae
-
show individual atoms in the molecule and the words between the atomo
-
each bonding pair is represented with a line
lone pairs are not shown
it
↑
H C H G
CHA
-
Hz g
-
4e g CO2 0 = c = 0
. .
I / &
H H H
HCN H -
C = N
Exceptions to the Octet Rule 13 82 24
. .
-
Goron (B) , hydrogen (H) ,
and hellum (He) have less ability to attract electrons to form a complete octet (8 electrons)
Expanded octets
-
atoms in periods 3-7 can bond with other atoms in such a way that they end up with more than 8 electrons in their octets
-
they are able to do this because of their d orbitals in the outer shells that can accept electrons
-
If you end up with an extra pair of electrons ,
this can be placed onto the central atom as a lone pair ,
as long as it's in the 3rd period or higher
Complex Lewis Dot Diagrams
1. count total valence electrons from all atoms .
If it is charged subtract or add the
corresponding electrons
,
with unpaired electrons the central atom(r) the other atoms around it
. Atoms
2 the most is .
Arrange
each pair of atoms to represent
. Draw one pair of
3 electrons between a
single rund
Fill octets for all until you run
.
4 atoms starting at the outside and then the central atomcs) out of electrons
electrons for the central atom ? More lone pairs to form
·
. Not enough double/triple words
Resonance structures
-
If there is more than one possible Lewis structure ,
the several possibilities are called resonance structures
-
Molecule/polyatomic
the On will flip back and forth between the different resonances
-
the electrons more out the atoms have not
- - , -
N N
& &
:% . .
0
i
:... O..
Bond order 20 . 02 23.
-
refers to the number of lands cringle double triple
, ,
·
due to resonance structures , an atom might have an effective bond order that isn't a whole number
total bonds
-effective number of Fonds/bond order :
central atom
atoms conded to
4) e .
. wond order
g for NOs
v
- - -
N 3 bonds
= 1 5 . effective bonds
& & 2 atoms
00 00
, complex Lewis Dot Diagrams with Bond order Practice
...
-- g
G
NO
, To
I : o
- o
= 1 .
5 effective bonds
- -
3
30 =/
3
effective Goed
-
-
2
~
2
- - -
2
--
0 G
=
2
5
-
< Y
ori-o. dro
effective bonds
-
Os 1 .
-
-
Ho
-
= I effective cond
Formal Charge
-
In some cases the atoms In a molecule can be arranged in different ways when drawing a Lewis Diagram
,
-
formal charges are calculated to identify the most stable/likely structure
the most stable structure the one which the formal closest to o
-
is in charges are
-
the sum of the formal charges on a neutral atom will be
polyatomic will be equal to the overall charge of the
-
the sum of formal charges on a lon ion
-
formal charge = valence e in an atom-clone e + number of bonds)
↳ e .
.
g · = c = :
0 = C- :
· = 0 =
S C 000000
valence 6 & 6 6 G 6 G &
lone bond 6 & 6 5 - 7 6 - 6
pair +
0 2 -
2
O 8 8 1 0.
formal charge
Bond Length and Bond Energy
~
triple bonds are shortest , then double then , single
rand the amount of energy required to make a chemical rond
-
energy is
bond energy harder bond to break
higher
-
=
-
shorter bonds have higher bond energy
Glucose Molecule (CH , 200)
!
H
H
......
H
" ↓
"
- &
% ::::.
"
:
:
0 :
it it it it if it
Molecular
↑
shapes 21 02 24
.
.
-
Stereochemistry :
studying the 3D shapes of molecules
-
VSERP (Valence Shell Electron Pair Repulsion) theory predicts the shape
4) e-pairs repel each other so they want to spread as far as possible around an atom
VSERP BASICS
-
lone pairs take up more space than a bonding pair
-
repulsion between2 lone pairs is the greatest
-
repulsion between I sanding pairs is the least
-
double bonds can be treated as
single bonds in terms of repulsion with other pairs
VSERP Symbols
- A represents central atoms
-
X represents any atom bonded to central atom
'E' represents a lone pair e on central atom
-
-
X + E represents the number of charge clouds surrounding the central atom
'
-
AXmE , where in is the number of bonded atoms and in is the number of love pairs on the central atom
normal/ backward
f l a t-
1111II/I
>
forward band
angle
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller penelopefurtado12. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $5.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
59523 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now