1/2O-Intro To Organic And Alkanes Flashcards
What’s a homologous series
Series of compounds containing the same functional group (atoms causing molecules to have similar chemical properties)
Gradual change in physical properties
Each member differs by CH2
What’s general formula
Algebraic formula for a homologous series
What’s structural formula
Shows arrangement of atoms in a molecule (structure around each carbon)
What’s displayed formula
Shows all the bonds and atoms present in a molecule
What’s skeletal formula
Organic formula contains carbon skeleton where each point represents a carbon.
IUPAC rules
Practise questions in purple booklet
IUPAC prefixes
2- di
3- tri
4- tetra
5- pent
6-hex
What’s the functional group of an alkane
CnH2n+2
What’s the functional group of alkenes
C=C
What’s the functional group of halo/halogeno alkanes
Has F,Cl,Br,I atom in it
What’s the functional group of an alcohol
-OH
What’s the functional group of an aldehyde
H-C=O
(Hydrogen bonded to carbon)
What’s the functional group of a ketone
C-C=O
(Carbon bonded to the rest of an alkane chain)
What’s the functional group of a carboxylic acid
C=O
|
OH
What’s an isomer
Molecules with the same molecular formula but the atoms are arranged differently
What are the 3 types of structural isomerism
Positional
Functional group
Chain
What’s positional isomerism
Functional group is attached to main chain at different points
eg 1-chloropropane (chlorine on carbon 1)
And
2-chloropropane (chlorine in carbon 2)
What’s functional group isomerism
A molecular formula could represent molecules with different functional groups
eg C2H6O could form an alcohol or an ether
What’s chain isomerism
The hydrocarbon chain is arranged differently (branches)
Are alkanes saturated or unsaturated hydrocarbons
Saturated
What’s petroleum
Mixture consisting mainly of alkanes
How can a mixture of hydrocarbons be separated and what does it form
Fractional distillation, fractions form depending on the boiling point of the hydrocarbons
What’s cracking
Breaks C-C bonds in long alkane chains
What are the conditions needed for thermal cracking
High pressure
High temps
Produces a high percentage of alkenes
What are the conditions needed for catalytic cracking
Slight pressure
High temps
Zeolite catalyst
Produces motor fuel and aromatic hydrocarbons
Why is it economical to crack hydrocarbons
Cracking produces shorter hydrocarbon chains which are more useful and in demand, this means demand can be met
What are alkanes used for
Fuels
How do alkanes and organic compounds combust
Completely and incompletely under high temperatures
What do catalytic converters do
Remove nitrogen oxides, carbon monoxide, carbon and unburned hydrocarbons from internal combustion engines
What does the combustion of hydrocarbons containing sulphur produce
Sulphur dioxide causing air pollution
How is sulphur dioxide removed from flue gases with calcium oxide or calcium carbonate
Calcium oxide/carbonate slurry and water sprayed into flue gas neutralising it forming calcium sulphite, oxidised into calcium sulphate (gypsum) to be used in plaster or plasterboard
What’s a free radical
A reactive species which possesses and unpaired electron
Represented with a dot
What are the steps of a free radical mechanism
Initiation, molecule turned into two radicals Br2 —> 2Br•
Propagation, molecule + radical (formed in initiation) —> radical + molecule, then radical (formed from eq above) + molecule —> radical + molecule
CH4 + Br• —>CH3• + HBr
CH3• + Br2 —> Br• + CH3Br
Termination, radical + radical —> molecule
Br• + Br• —> Br2
CH3• + CH3• —> C2H6
CH3• + Br• —> CH3Br
Practise Qs
Conditions for free radical substitution
Initiation requires uv light
What type of isomerism is E-Z and how does it occur
Stereoisomerism
Due to restricted rotation about the planar C=C double bond (found in alkenes)
Two different groups attached to each C atom
What is stereoisomerism
Same structural formula but different spatial arrangement of atoms
What are the priority rules when naming E-Z isomers
Look at each carbon, the atom attached to each carbon with the highest atomic number gets circled
If these molecules are on the same side they are [Z]
If they are on opposite sides they are [E]
