Organic Chem Flashcards
What is an electrophile?
An electron-deficient species is therefore attracted to parts of the molecule that are electron rich. Electrophiles are positive ions or have a partial positive charge. Eg No2 ^+, H+
Nucleophile
an electron-rich species which is therefore attracted to parts of the molecules which are electron deficient. Nucleophile have a lone pair of electrons and may also have a negative charge
Eg Cl-, OH-, NH3
homolytic fission
when a covalent bond breaks by splitting the shared pair of electrons between the 2 products. (The products that got the same # of electrons to produce 2 free radicals, each with an unpaired electron.
X:X –> X. + X.
homolytic fission is represented with a one sided arrow
what does HETEROLYTIC FISSION mean
When a covalent bond breaks with both the shared electrons going to one of the products (the products get a diff number of electrons)
Produces 2 opposite charged ions
X:X —> X: + X
—> <— 2 headed arrow represents heterolytic fission
Saturated meaning?
COMPOUNDS THAT ONLY CONTAIN SINGLE BONDS
EG ALKANES
UNSATURATED meaning?
COMPOUNDS WHICH CONTAIN 1 OR MORE DOUBLE OR TRIPLE BONDS
EG ALKENES, ARENES
Aliphatics
COMPOUNDS WHICH DO NOT CONTAIN A BENZENE RING; MAY BE SATURATED OR UNSATURATED
EG ALKANES & ALKENES
Arenes
compounds which contain a benzene ring; they are all unsaturated compounds, eg benzene and phenol
Number of carbon: 1
Longest chain name?
Side chain name?
Meth-
methyl-
Number of carbon: 2
Longest chain name?
Side chain name?
Eth-
Ethyl
Number of carbon: 3
Longest chain name?
Side chain name?
prop-
propyl
Number of carbon: 4
Longest chain name?
Side chain name?
but-
butyl
Number of carbon: 5
Longest chain name?
Side chain name?
pent-
pentyl
Number of carbon: 6
Longest chain name?
Side chain name?
hex-
hexyl
complete combustion equation, and what condition
lots of oxygen
product: carbon dioxide (CO2) + H2O
Incomplete combustion and what condition
lack of oxygen
carbon monoxide (CO) + H2O
OR
Carbon (Soot) + H2O
Carbon dioxide environmental impacts
Greenhouse gas, global warming and climate change
Carbon monoxide environmental impacts
Is toxic to humans as combines with haemoglobin in the blood which prevents oxygen from being carried
Unburned carbon environmental impacts
effect on human health, especially the respiratory system, they also act as a catalyst in forming smog in the air.
What do we know about combustion ( the variables)
The more limited the air, the less heat that is generated
The greater the number of carbon atoms the more energy that is produced
Free radical substitution. Step 1
Initiation. Photochemical homolytic fission. The splitting of the shared pair of electrons between the 2 atoms
Free radical substitution. Step 2
Propagation, chain reaction. Always start with 1 free radical and 1 normal molecule and end with the same.
Free radical substitution. Step 3
Termination
Organic chem conversion map
see on ipad
Alkanes (number of bonds)
single
Alkenes (number of bonds)
double
Arenes/aliphatics/aromatics/benezene (C6H6) physical and chemical features
equal bond lengths within benzenes structure (proves dislocation) single bonds is diff length to a double bond, if we measure benzene it is the same length, thus must have only single bonds.
not very reactive would expect c to be if it had a double bond
Alkynes (number of bonds)
triple
what test can we do to distinguish an alkane from an alkene?
Reaction with bromine is the standard test for the presence of a double or triple bond between carbon atoms. A solution of bromine changes from ORANGE TO COLOURLESS if the molecule is unsaturated.
Alkane, if nothing happens its and alkane
if orange to colourless its and alkene
making an alkene to an alkane
list out everything: Hydrogen, halogens, hydrogen halides and water
Reaction with hydrogen (H2) is called hydrogenation the catalyst is PtO2/Pd
Reaction with chlorine, Bromine, Iodine, Flouride …
Alkene —-> Di Halo Alkane
reaction with hydrogen halides
Alkene + H - hailde —> Halo Alkane
The addition of water known as hydration converts the alkene into alcohol. Sulfuric acid is a catalyst
Conditions: Heat with steam and catalyst of concentrated H2SO4.
Aldehydes’s general formula (chemical R)
R-CHO (end)
Ketone’s general formula (chemical R)
R-CO-R (middle)
If carbonyl (C=O) is at the end it is a…
what is it’s ending?
aldehyde and ending is -al
If carbonyl (C=O) is at the middle it is a…
what is it’s ending?
ketone and ending is -one
Alcohols general formula
Cn H2n+OH
what is alcohol’s ending?
-ol
What chemical identifies an Alcohol
-OH (hydroxyl)
Classification of alcohol
Classification identifies the C atom that has the OH group attached.
- primary 1* - attached to 1 R group (at the end of the carbon)
- primary 2* attached to 2 R groups (at a branch of a carbon atom)
- Tertiary 3* attached to 3 R groups
what alcohols can be oxidised? What are their oxidising things?
Primary and secondary, acidified potassium permanganate (H+/KMnO4) or acidified Potassium dichromate (H+/K2Cr2O7)
what is the steps of alcohol oxidation? for Aldehyde? (Primary)
Isolate the aldehyde, you need to heat up the 1* alcohol solution and distil out the vapour as fast as it is formed Aldehyde has a lower boiling point and vaporises.
what is the steps of alcohol oxidation? for carboxylic acid? (Primary)
heat and reflux. attach a condensing tube to your vapour so that your vapour condenses before they can escape. Aldehyde condenses and is forced to further oxidise into carboxylic acid
Isomers
compounds with the same molecular formula but different arrangements of atoms
what is the bromine water test for?
Alkenes can decolourise bromine water, but alkanes cannot.
What class of Halogenalkane can SN1 react with
tertiary 3*
How many steps is SN1
2
Is SN1 transition state or reaction intermediate
carbocation intermediate
type of solvent the reaction SN1 needs to happen in
polar protic
type of bond fission in SN1
heterolytic fission
What class of Halogenalkane can SN2 react with
Primary 1*
How many steps is SN2
1
Is SN2 transition state or reaction intermediate
reaction intermediate
type of solvent the reaction SN2 needs to happen in
polar aprotic
type of bond fission in SN2
heterolytic
The molecularity of SN1
unimolecular
The molecularity of SN2
Bimolecular
SN1 relative rate of reaction
3* > 2* >1*
SN2 relative rate of reaction
1>2>3*
Change in sterochemisty SN1
50/50 mix of enantiomers (racemic mixture, optically inactive)
Change in sterochemisty SN2
inversion of configuration
which reaction is faster SN1 or SN2
SN1
