Structures and properties
magnatism
Ferromagnatism
Diamagnetism: Repel
Paramagnatism: weak attraction
solids
covalent network solids
Form a lattice of continuous covalent / polar-covalent bonds
Metallic
Metal properties can be explained by considering them as positive ions
ionic
Solids formed by ionic bonds between metal cations and non-metallic anions
Polar Molecular Compounds
Compounds with bond dipoles and molecular dipoles Gives higher boiling points
Non-Polar Molecular Compounds
Compounds without bond dipoles only have London Forces between molecules (low melting points)
London forces
London forces form due to the attraction between instantaneous dipoles
Bonds
Intra-molecular
Bonds between molecules
Inter-molecular
Bonds within a molecule (covalent or polar covalent)
VSPER Theory
Electrostatic Potential
A map of electrostatic potential measures the force acting on proton due to the molecule’s distribution of electrons/protons
Molecular Orbitals
VSEPR Theory was based on experimental evidence (electro densities).
AXE Notation
AXE Notation simplifies the identification of VSEPR shapes
Valence Shell Electron Pair Repulsion
A theory used to predict the 3-dimensional geometry of molecules
Ionization energy
Atomic radius
Greater nuclear charge pulls electrons closer to the nucleus
Coulomb’s Law
electrostatic attraction between two charged particles
Cations And Anions
Positively and negatively charged ions either attracting protons orelectrons
Lewis Theory
A Lewis acid is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base
Orbitals
Hydrogen obritals
f orbitals
d Orbitals
p Orbitals
probability distribution for where an electron may be found
The Uncertainty Principle
Exact positions of electrons cant never be determined
De Broglie Waves
proposed that electrons exist as matter waves around the nucleus, with only complete integer values of the electron wavelength permitted.
Quantum theory of light
All electromagnetic radiation is made up of electric and magnetic fields
Particle Theory
atoms or elementary particles themselves are not real, they form a world of potentialities or possibilities
Atomic Theory
Rutherford´s nuclear atom: all positive charge and most of the mass is concentrated in the nucleus of the atom. The electrons are found in the empty space around the nucleus.
Thomson´s model of atom proposed the plum pudding model: a sphere of positive electrical charge in which electrons are embedded
Daltons atomic theory: reintroduced the atomic theory based on the available evidence
The Inter-Relationships of chemistry
Equilibrium
Titration Calculations
Acid-Base Neutralization
Titration Curves and Buffers
KB Calculations
KA Calculations
opH and pOH Scales
Logarithmic Function
Weak Acids
Weak acids do not completely ionize
Acids and bases
Lewis Acid-Base Theory
Lewis Base
an electron pair donor. Anions or other species with lone pairs are Lewis bases
Lewis Acid
an electron pair acceptor. Cations or species with incomplete octet are Lewis acids.
Brønsted-Lowry Theory
BL Bases
proton acceptor in a reaction
BL Acids
Subtopic
protons donors in a reaction
Arrhenius Theory
Arrhenius Bases
substances that dissociate to form hydroxide ions
Arrhenius Acids
substances that dissociate to form hydrogen ions
Formation of a Precipitate
Rice ( reaction, Initial, change, equilibrium)
Reaction Quotient
equilibrium constant equation is solved under potentially non-equilibrium conditions, this “trial” calculation is called reaction quotient.
Solubility Product
KSP
Saturated Solutions
Crystallizing
Dissolving
Solubility Equilibrium
The Equilibrium Law Expression
Rice Tables
Concentration-Time Graphs
K Value
Dependant on tempature
Le Chatelier’s Principle
a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change to reestablish an equilibrium
Enthalpy changes favour the exothermic direction of a reaction since these involve products with lower potential energy
Disorder
the greater the disorder the higher the entropy
Dynamic equilibrium
dynamic equilibrium is disturbed by changing the conditions
Entropy
Systems tend to move spontaneously toward a state of maximum randomness or disorder
Equilibrium Systems
eactions actually take place in both the forward and reverse directions at the same time
Spontaneous Reactions
A spontaneous reaction is a reaction that favors the formation of products at the conditions under which the reaction is occurring
At equilibrium, reactions actually take place in both the forward and reverse directions at the same time
Thermodynamics
Factors affecting rate of reaction
Pressure
Surface area
Catalysts: A catalyst is a substance that changes the rate a reaction without being consumed
Enzymatic Catalyst
Proteins
Inhibitors:
Heterogeneous catalyst
Ex. uv radiation
Adsorption
Homogeneous catalyst
Ex. Food oils
Temperature
Reaction Mechanisms
Molecularity
Molecularity is the number of particles (molecules or ions) involved in an elementary step
Multistep reactions
Many reactions occur as a series of simpler elementary steps.
Elementary (Single) Step Reactions
reactions that only involve single events where bonds break and reform
Zero-order Reactants
The reactant concentration does not affect the rate
Collision theory
The reactants must collide with sufficient energy for a reaction to occur
Collision Geometry
Even if molecules with sufficient energy collide, a reaction may still not take place
Rate of Reaction
The study of the rate or “speed” of a chemical reaction
Enthalpy calulations
Summation method
Additivity method
Hess’ Law
Another way to determine ΔH is to utilize the concept that the overall enthalpy change of a system
Heat Capacity
Amount of heat required to change The temperature
Calorimetry Method
an experimental technique for measuring energy change in chemical reactions
Bond Energy Method
A chemical reaction can be viewed as a series of bonds breaking and reforming
Enthalpy
Enthalpy (heat content, H) is the total energy possessed by a system
Molar Enthalpy
Energy change associated with the reaction/transformation given ONE mole of a substance
Reaction Enthalpy
Energy change associated with a reaction/transformation given certain conditions
System and Surroundings
surroundings is everything else
system is the sample being observed
Organic chemistry
polymerization
A chemical reaction that bonds many monomers together to form a polymer
polymers
condensation
These are formed by reactions between an acid and alcohol
addition
arge molar mass formed by the reaction of smaller molecule called monomers
Functional groups 2
Amides
The amide has a structure similar to the ester however the oxygen atom
Amines
secondary
Secondary amines are named using a different system
Tertiary
longest chain with N attached
Amines are classified as primary, secondary or tertiary depending on the number of alkyl groups (R groups) bonded to the nitrogen.
Esters
Esters have an oxygen between two carbons (R-O-R)., however carbon-1 also has a carbonyl (C=O)
They are volatile liquids and are found in fruit flavours
Ethers
Ethers have an oxygen between two carbons (R-O-R).
They are volatile liquids used as solvents, anaesthetics.
Functional groups
Carboxylic acids
When a hydroxyl (C-OH) and carbonyl (C=O) are on the same carbon, a carboxylic acid is formed
Ketone
Middle of chain
Aldehydes
End of chain
Both aldehydes and ketones contain the carbonyl functional group
Alcohols
Molecules containing the R-OH group (hydroxyl) are called alcohols
Isomers
Geometric Isomers
when 2 compounds contain atoms bonded in the same order, but they have a different spatial arrangement
ISOMERS are compounds with the same formula but different structures
aromatics
Amino acids
Hydrocabons
AROMATIC
Ring shape
ALIPHATIC
Open chain
HYDROCARBONS are organic compounds containing only carbon and hydrogen
Bonding capacity
Number of electrons out of the orbit
Cyclic
Alkanes and alkenes can commonly form rings.
Alkenes
Unsaturated hydrocarbons because they contain less than the maximum amount of H bonded to C
Alkynes
Triple bonds
Unsaterated
because they contain less than the maximum amount of H bonded to C
Alkanes
Double bonds
Saturated hydrocarbons because they contain more than the maximum amount of H bonded to C
Organic compounds
members of a large class of gaseous, liquid, or solid molecular compounds whose molecules contain CARBON
Electrochemistry
Agents
reducing agent
Oxidation Agent
Electrolysis
Electrolysis is the passing of a direct electric current through an electrolyte producing chemical reactions at the electrodes and decomposition of the materials
Electroplating
Electroplating uses an electric current to deposit metals at a cathode from a solution of aqueous metallic ions
Electrolytic Cells
Electrolysis is the splitting of stable compounds using an electric current
Hydrogen Half Cell
There are hundreds of possible combinations of half-cells, each with unique voltages
Cell Potential
Every combination of half cells will produce a unique electrochemical cell potential
Half reactions
Electrodes
CATHODE
The CATHODE is always the site of REDUCTION
CATIONS were defined as substances that move toward the CATHODE in any cell
ANODE
The ANODE is always the site of oxidation
ANIONS were defined as substances that moved towards the ANODE
electrochemical cell
Electrochemical cells (also called galvanic cells or voltaic cells) are devices used to generate electricity
Balancing redox equations
Oxidation Number
Oxidation Reactions
The substance that gains electrons is said to be reduced
The substance that loses electrons is said to be oxidized
Oxidation reactions were originally associated with the reaction of metals with oxygen
Reduction Reactions
Reduction reactions were originally associated with a loss (reduction) of mass in metal ores upon heating or reacting with carbon
Redox Chemistry
Redox (reduction/oxidation) chemistry deals with chemical reactions in terms of electron transfer
