0RGANIC CHEM - ranmdon facts Flashcards
(24 cards)
What is sterioisomers
same structural formula but different arrangement in space
Which of the other isomers (that we have already study) come under sterioisomerism
- Geometrical Isomerism (E-Z / Cis-Trans)
- Optical Isomerism (in molecules with chiral/asymmetric carbons)
What gases can catalytic converters remove from the exhausts.
Unburnt Hydrocarbons, and oxides of nitrogen
How and where is Sulphur dioxide removed from
It is removed from power station flur gases through the process o wet scrubbing, where a wet slurry of calcium carbonate (limestone) and/or calcium oxide. which is sprayed over the flue gases, the calcium in the alkaline slurry react with the SO2 in the flue gases.
out of all the halogens, which one has a similar electronegativty to carbon, making them the only haloalkane that’s non-polor
Iodine, has the closest electonegativity to carbon, making the C-I bond non-polar.
how can alkyl iodides undergo nucleophillic substiution even tho the C-I bond is non-polar
even tho the bond is non-polar and the alkyl iodide is highly polarisable, if a negative ions comes along behind the carbon, it can rpel the electrons in the C-I bond, inducing a dipole in bond, and making the carbon more +ve = a polar bond is now formed. and it can undergo nucleophillic substitution
what is the ferric test
a test to identify phenols, adding FeCl3 to a solution. a resulting violet solution is a postitive result.
how is resonance and acidity related as a general rule
a compounds whose conjugate base which shows resonance stabilty is said to be more acidic.
are alcohols more or less acidic than phenols
phenols are more acidic, cos of the due the stabilization of the phenoxide ion through resonance.
which acid out of benzoic acid and salycylic acid
salicyclic acid because, it has a hydrogen bond between the functional groups, making a stronger molecule.
what can be used to test for phenols and what is the result.
but also to distinguish phenols from benzyl alcohols (alcohols with a benzene subtituent)
Adding ferric chlroide - FeCl3 (or iron (III) chloride) to a solution of a phenol, turns into a vioet colour = a positive result.
How are alkoxides formed from alcohols
Highly reducing metals can react with alcohols, producing an alkoxide - the negatively charged alcohol ion. R-O-^
what 2 reaction of aromatic compounds are easier in phenols than they re in benzene and why.
- bromination
- Nitrification
both easier cos of the increase in electron density.
also with nitrification of phenol doesnt need the mixture of conc HNO3 and conc H2SO4 at 500 degrees - needed for benzene
out of the 2, which will form a more stable cabocation internediate
1. CH3C(^+)HCH3
2. H3CC(+^)HCH2-Br
and why
both are secondary cabocations, but 1 is more stable of a carbocation. cos the Br on the 2nd one is more electronegative, meaning it attracts the bonding electrons closer to itself.
- the already positive carbon, becomes more positive, making a less stable of a molecule.
- whenever a +ve or -ve charge become more +ve or more -ve, the molecule becomes less stable, cos the charge is more unevenly spread out.
give the main term used to explain cabocation stability, and summarise how it works.
(other than the inductuve effect)
https://www.youtube.com/watch?v=_mEJ1aYmYo4
- watch for visualising
Hyperconjungation, can explain why (3,2,1 .) carbocations are more stable than a methyl carbocation.
A methyl carbocation has 3 sp2 bonds, with 1 unhybridised p orbital, where the +ve charge resides. it is localised here, in this area - less stable.
- if you think about this methyl binded to another methyl group = a primary carbocation -»
one of the 3 sp3 hybridised bonds in the second carbon, will form parallel to the unhydridised p orbital on the first carbon, and can form a connection with each other. - the connectivity of theses orbitals is called hyperconjugation = and allows for the spreading of the +ve chagrge across the molecule, making primary carbocations more stable than methyl ones.
- essentially the electrons are also spread out evenly = more stable.
https://www.youtube.com/watch?v=_mEJ1aYmYo4
can a shifted carbocation, to form a more stable molecule, be classed as an isomer of it’s intial molecule.
yes or no
yes, it becomes a structural isomer cos of the methyl shift.
what is the Lucas test, what is the reagent mixture. and what mechanism occurs.
test to distinguish primary, secondary and tertiary alcohols. reagents - conc. HCl and anhydrous ZnCl2.
Sn1 mechanism.
what can picric acid also be known as
2,4,6-trinitrophenol
what is R and S in (latin) terms of chiral centres, and how can you assign R and S to a compound
R = Rectus = Right - clockwise
S = Sinister = Left - anticlockwise.
can assigned to enantiomers using the cahn-ignold-prelog rules. the clock starts at the atom with the highest atomic number, and follows from there.
- if the atoms go in clockwise direction, decreasing in atomic number, they are called
R-compound IUPAC name.
and the opposite for anticlockwise.
what is a carbenoid
an unusual reagent that can used as either a coarbon nucleophile or as a carbene in elimination.
what is the gringnard reaction and gridnard reagent.
reaction - ketones and aldehydes to tertiary and secondary alcohols.
reagent - organomagnesium halide.
when can we use iso- as prefix when naming organic compounds.
we can use it to name branched molecules, but only when the branching is occuring at the second carbon whilst that same carbon is bonded to a methyl group
formic acid - aka
methanoic acid
acetic acid - aka
ehtanoic acid
