Organic Flashcards
Carbon atoms can be arranged in
Straight chain
Branched chain
Rings
Simplest homologous series is
Alkanes
General formula of alkanes
CnH2n+2
Catenation
Form bonds with itself multiple times
Homologous series definition
Series of compounds of similar structure in which each member differs by a common repeating unit e.g CH2
- same general formula
- same functional groups
- differ by CH2
- similar chem properties but different physical
Root of name is
N. Carbon atoms in longest continuous chain
Prefix of name is
Before root and shows the position and identifies branch
Suffix of name is
Added after root indicating functional group
What is CH3 side chain refered to as
Methyl
What is CH3CH2 side chain refered to as
Ethyl
What is CH3CH2CH2 side chain refered to as
Propyl
Alkyl general formula
CnH2n+1
Make sure to order the prefixes in _____ order
Alphabetical
Each side chain is given its own ____
Number / locant
If a group occurs more than once then a ___ is used on start of prefix e.g___
Multiplier
Di
Tetra
Tri
E.g 2,3-dimethyl…
Name each part of this name 3,4-dimethylpentan-2-ol
Locant: 3,4
Multiplier: di
Prefix: methyl
Root: pentan
Locant: 2
Suffix: ol
General formula definition
Represents all members of homologous series e.g CnH2n
Alkyne general formula
CnH2n-2
Molecular formula definition
Shows actual number of atoms of each element in 1 molecule e.g C4H10
Empirical formula definition
Simplest whole number ratio of atoms of elements in compounds
Structural formula definition
Minimal detail which atoms or groups of atoms are attached to eachother in one molecule of a compound e.g CH3CH2CH2CH3
Displayed formula definition
Shows all atoms and bonds between them in one molecule of a compound
Functional group definition
Group of atoms which gives an organic compound its characteristic properties and reactions
What is carboxylic acid functional group
C doubled bond to an O and single bonded to an OH
alkenes functional group
C double bond C
Alkyne functional group
C triple bond C
Halogenoalkanes functional group
C—X (halogen)
Amine functional group
N single bonded to 2 Hydrogens
Nitrile functional group
C triple bond N
Alcohol functional group
O—H
Ether functional group
C—O—C
Aldehyde functional group
C double bond O and single bond H
Ketone functional group
C single bonded to 2 Carbons and double bonded to an oxygen
Ester functional group
Look in book
Acyl chloride functional group
Look in book
Amide functional group
Look in book
Nitro functional group
Look in book
Sulphonic acid functional group
Look in book
Skeletal formula definition
Shows simplified organic structure by leaving C-H skeleton and drawing on functional groups..
Ending of a ketone
One
Suffix of aldehyde
Al
Suffix of Carboxylic acid
Oic acid
Suffix of acyl chloride
Oyl chloride
Suffix of amide
Amide
Suffix of ester
yl oate
Suffix of nitrile
Nitrile
Suffix of sulphonic acid
Sulphonic acid
Suffix of ether
Oxy ane
define isomer
molecules with same molecular formula whose atoms are arranged differently
define structural isomer
isomers that have same molecular formula but different structural formula
define stereoisomer
molecules with same structural formula but a different spatial arrangement of atoms
what are the 2 classifications of isomer
stereoisomer and structural isomer
what are the 3 classifications of structural isomer
position isomer
chain isomer
functional group isomer
what are the 2 classifications of stereoisomers
geometric isomer
optical isomer
what is a chain isomer
type of structural isomer
change in arrangement of carbon chain
similar chemical properties
differing physical isomer
more branching=lower BP
what is a position isomer
same carbon skeleton
same functional group
functional group in different position
similar chemical properties
differing physical properties
what is a functional group isomer
same molecular formula
different functional group
different chem properties
different physical properties
what functional groups are functional group isomers of each other
alcohols and ethers
aldehydes and ketones
carboxylic acids and esters
alkenes and cycloalkanes
do C-C bonds have free rotation
yes
do C=C bonds have free rotation
no
do C=C bonds have free rotation
no
what type of isomers are E/Z
geometric stereoisomers
difference between E/Z isomers
E= highest atomic number of first attached atoms opposite
Z=highest values same side/together
define redox
reaction involving reduction and oxidation
define addition reaction
a reaction in which 2 molecules are added together to form a single product
define substitution reaction
a reaction in which 1 atom or group of atoms is replaced by another atom or group of atoms
define elimination
a reaction that produces an unsaturated product by loss of atoms or groups of atoms from adjacent carbons
define hydrolysis
a reaction in which a compound splits apart in a reaction involving water
define addition polymerisation
an addition reaction in which small molecules (monomers) are joined together forming a giant molecule (polymer)
define free radical
species with an unpaired electron
define homolytic fission
if a covalent bond breaks homolytically then each atom keeps one electron
define heterolytic fission
one atom takes both of the electrons from the covalent bond
define nucleophile
electron pair doners
negative ions or molecules with a lone pair of electrons that attack positive ions/centres
define electrophile
electron pair acceptors
positive ions/molecules with a avacant orbital that attack negative ions/centres.
outline order of fuels produced from fractional distillation from low to high temp
refinery/fuel gases 20
petrol/gasoline 40
naptha 110
kerosene 180
diesel oil 250
fuel oil 300
lubricating oils 300
bitumen
in fractional distillation what does the BP depend on
size of molecules as larger= more electrons= stronger london forces
in fractional distillation what does separation of crude oil depend on
boiling point
temperature of the fractionating column ——— downwards
increases
small molecules condense at the —— of the fractionating column
top (lower T)
define cracking
conversion of large hydrocarbons to smaller molecules by breakage of C-C bonds
define reforming
turns straight chain alkanes into branched and cyclic alkanes and aromatic hydrocarbons which burn more cleanly and are used to gives fuels a higher octane number
3 economic reasons for catalytic cracking
- petroleum fractions with shorter C chains have higher demand (e.g petrol & naptha)
-makes use of longer chain HCs
-products are more usefu and valuable than starting materials. smaller alkanes used for motor fuels
what type of process is cracking
chemical- breaks C-C strong covalent bonds
what type of process is fractional distillation
physical- splitting of weak london forces between molecules
define fuel
releases heat energy when burnt
is combustion of alkanes exo or endo
exothermic
when do alkanes complete combust
excess oxygen is present
products of complete combustion
only CO2 and H2O
when do alkanes incomplete combust
limited amount of oxygen
what are the products of incomplete combustion
CO and/or C and H2O
what releases more energy, CC or IC
complete combustion
what are the issues associated with carbon as a IC product
carbon (soot) particulates can cause global dimming/ reflection of sunlight
what are the issues associated with carbon monoxide as a IC product
highly toxic but odourless gas, binds with haemoglobin in RBC which reduces oxygen intake
how is sulphur dioxide a pollutant from combustion
sulphur containing impurities are found in petroleum fractions which produce SO2 when burned
S + O2→SO2
CH3SH+CO2→SO2+CO2+2H2O
why is SO2 a pollutant/bad
SO2 is acidic and will dissolve in atmospheric water and can produce acid rain
describe how are nitrogen oxides a pollutant in combustion
from reaction between N2 & O2 in car engine
explain how nitrogen oxides a pollutant in combustion
increase in T and spark in engine provides sufficient energy to break strong N2 bond
N2 + O2→2NO
N2 + 2O2→ 2NO2
why is NOx a pollutant/bad
NO= toxic and can form photochemical smog
NO2= toxic and acidic (can form acid rain)
purpose of catalytic converters
remove CO, NOx, and unburned hydrocarbons from exhaust
equation of reaction between CO and NO in a catalytic converter
2CO + 2NO→2CO2 + N2
equation of reaction between unburned HC (e.g octane) and NO
C8H18 + 25NO→8CO2 + 12.5N2 + 9H2O
catalyst used in catalytic converters
precious metals, platinum, palladium, rhodium
structure of catalytic converter
ceramic honeycomb coated with a thin layer of catalyst metals, large SA
what source do most FFs come from
crude oil
why is crude oil bad
non renewable
pollution
2 examples of biofuels
alcohols and biodiesel
why are biofuels good, 5 reasons
-renewable
-more carbon neutral
-reduce FF usage
-allow FFs to be used as feedstock for org compounds
-no risk of large scale pollution
why are biofuels bad, 4 reasons
-less food crops may be grown
-land not used to grow crops
-rainforests cut down to provide land
-shortage of fertile soils
what product does homolytic fission produce
2 free radicals
what is a free radical
species with an unpaired electron
what product does heterolytic fission produce
ions
most organic reactions occur via ________ fission
heterolytic
what are 3 steps of free radical substitution
initiation
propogation
termination
overall reaction equation for free radical substitution of methane and chlorine
CH4 + Cl2→CH3Cl + HCl
what are the conditions needed for intiation in FRS
UV light
why is UV light needed in intiation
supplies energy to break Cl-Cl bond
why is _____ bond broken in initiation
Cl-Cl is broken in preference to others as it is the weakest bc bond is longer as Cl is larger than H
what does initiation form/ is characterised by
forms free radical from non free radical
what is the method of bond breaking in initiation in FRS
homolytic fission
what is step 1 within propogation in FRS
Cl free radical (formed in initiation) is very reactive and reacts with other species to form another free radical. reacts with H on methane to form methyl free radical
what is step 2 within propogation in FRS
methyl free radical (or other e.g ethyl) reacts with a Cl2 molecule (not all were broken in initiation) to produce main product and a Cl free radical. causes chain reaction
how can you recognise a propogation reaction
free radical in reactants and products
what occurs in termination
2 free radicals collide and do not generate further free radicals, chain is terminated
what are the 3 possible termination reactions
*CH3 + *CH3→CH3-CH3
*Cl + *CH3→ CH3-Cl
*Cl + *Cl→ Cl2
free radical substitution equation of methane and chlorine
Cl2 + CH4–> CH3Cl + HCl
do alkanes or alkenes have a higher Mp and Bp
alkanes
increasing carbon chain length _____ BP
increases
increasing number of atoms _____ BP
increases (london forces), increasing IMFs increases energy required to separate molecule, which increases BP
increasing branching ______ BP
decreases
are alkenes soluble in water
no, they are non-polar so immiscible in water
reagent and conditions for prep of alkenes from halogenoalkanes (elimination)
conc sodium or potassium hydroxide
heat under reflux in anhydrous ALCOHOLIC SOLUTION
reagent and conditions for prep of alkenes from alcohols (dehydration)
conc sulphuric acid or phosphoric acid
heat under reflux
difference between halogenoalkaes and halogenoarenes
in halogenoalkanes the halogen is attached to aliphatic skeleton whereas in halogenoarenes it is attached to aromatic skeleton
mechanism to form halogenoalkanes from alkanes
free radical substitution
mechanism to form halogenoalkanes from alkenes
electrophillic addition
mechanism to form halogenoalkanes from alcohols
nucleophillic substitution
enthalpy/strength of bonds (x) _____ down group
decreases, bond length increases down group due to increasing atomic radius. therefore halogenoalkanes reactivity increases down group
halogenoalkanes reactivity __________down group
increases
what attacks halogenoalkanes
free radicals and nucleophiles (attacks the polar C-X bond)
why don’t electrophiles attack HA
bonds in HA are single, not electron rich and electrophiles are electron pair acceptors
what are the reagents and conditions of reacting aq alkali with HA
sodium or potassium hydroxide
heat under reflux in AQUEOUS SOLUTION
what are the reagents and conditions of reacting aq alkali with HA
sodium or potassium hydroxide
heat under reflux in AQUEOUS SOLUTION
what is the mechanism of reacting aq alkali with HA
nucleophilic substitution
what is the product of reacting aq alkali with HA via nucleophilic substitution
alcohol
what is the nucleophile of reacting aq alkali with HA via nucleophilic substitution
OH- or water
what is the mechanism of hydrolysis with water of HA
nucleophilic substitution
what is the product of nucleophilic substitution, hydrolysing with water
alcohols
what happens when aq silver nitrate is shaken with a HA
they are immiscible so the displaced halide combines with a silver ion to form a precipitate
AgCl- white precipitate
AgBr- cream precipitate
AgI- yellow precipitate (fastest due to lower bond enthalpy of C-X therefore more reactive)
what is the product from reacting HA with cyanide
nitrile
what are the reagents and conditions for reacting cyanide and HA
potassium or sodium cyanide
heat under reflux in aq alcoholic solution
what is the nucleophile when reacting sodium cyanide with HA
cyanide ion
what is the importance of the reaction between cyanide and HA
extends the carbon chain by one carbon atom, nitriles can undergo hydrolysis and reduction (useful)
what is the mechanism of reacting cyanide and HA
nucleophilic substitution
is nucleophilic substitution heterolytic or homolytic bond breaking
heterolytic
what is the product from reacting ammonia with HA
amine
what are the reagents and conditions of reacting ammonia with HA
ammonia in excess (to ensure a salt isn’t formed
what are the reagents and conditions of reacting ammonia with HA
ammonia in excess (to ensure a salt isn’t formed but an amine)
conc sol of ammonia in ethanol, heat under pressure in a sealed tube
what is the nucleophile in reacting excess ammonia with HA
:NH3
what is the mechanism of reacting HA with ammonia
nucleophilic substitution
what is the problem with amines as a product from the reaction between ammonia and HA
amines are nucleophiles (lone pair on N) therefore can attack another molecule of HA forming a 2* amine, this is also a nucleophile so can react again to for 3* … eventually producing a ionic quaternary ammonium salt
what is (CH3CH2)2NH
diethylamine, a 2* amine
elimination always forms _____ products than reagents
more
elimination produces ______
alkenes
what makes elimination occur vs substitution
the solvent, aq=substitution, alc=elimination
in elimination (alc) what is the role of the OH-
base
explain the role of OH during elimination in alc sol
OH- attacks one of the hydrogen atoms on a carbon atom adjacent to the carbon bonded to the halogen. OH- acts as a base (proton acceptor)
both elimination and ________ ____ occur at the same time but varying the ______ can influence which ______ dominates
substitution
can
solvent
mechanism
product of 1-chlorobutane with KOH (aq)
butan-1-ol and KCl
product of 1-chlorobutane with KOH (alc)
but-1-ene KCl
what is the product from reaction between HA and sodium/potassium hydroxide in alc conditions
alkenes as elimination occurs
what is the mechanisim in the reaction between HA and sodium/potassium hydroxide in alc conditions
elimination
what are the reagents and conditions in the eliminationreaction between HA and sodium/potassium hydroxide
conc potassium/sodium hydroxide
heat under reflux in ‘dry’ anhydrous condiitons ALCOHOLIC solution
with ________ HA _______ products can form
unsymmetrical
multiple