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ORGANIC CHEMISTRY - SOME BASIC PRINCIPLES AND
TECHNIQUES|VERIFIED ANSWERS 100%|
catenation-✓✓ability of carbon atoms to bond with each other to form chains hybridisation formula-✓✓steric number = sum of sigma bonds + lone pairs relation of hybridisation and bond lengths-✓✓more s character, closer to nucleus, forms shorter and stronger bonds relation of hybridisation and electronegativity-✓✓greater s character of hybrid orbitals, greater the electronegativity which is more electronegative? carbon with sp/sp3 hybridisation-✓✓sp 50% s character which is more reactive, pi or sigma?-✓✓pi bond because the electrons are easily available to the attacking reagents as the electron cloud lie above and below the plane of bounding atoms note: shape and hybridisation is found out by steric number-✓✓ note: mostly CO is C double bond O-✓✓ classification of organic compounds-✓✓aliphatic or open chain & cyclic or closed chained cyclic → alicyclic & aromatic aniline-✓✓benzene with NH anisole-✓✓benzene with OCH acetophenone-✓✓benzene with COCH unsaturated and saturated-✓✓alkyne, alkene alkane isopropyl-✓✓(CH3)2CH- sec-butyl-✓✓CH3CH2CH(CH3)-R isobutyl-✓✓(CH3)2CHCH2- tert-butyl-✓✓(CH3)3C- neopentyl-✓✓-CH2C(CH3)
rules i need to note-✓✓- lower number is given to that substituent group coming first in the alphabetical order
- in alphabetical order, iso and neo are considered but sec and tert are not
- careful when naming alkyl groups
- in cyclic compounds, more branched carbon gets lower order
- for naming benzene compounds, numbering is chosen such that the next substitute t group gets the lowest number possible order of decreasing priority in functional groups-✓✓-COOH -SO3H -COOR -COCl -CONH -CN -HC=O >C=O -OH -NH >C=C< -C≡C- prefixes -NO -X -R -H5C halides prefix-✓✓chloro, bromo, etc. alcohol prefix and suffix-✓✓hydroxy- and -ol aldehydes prefix and suffix-✓✓oxo- -al ketone prefix and suffix-✓✓oxo- -one nitriles prefix and suffix -C≡N-✓✓cyano nitrile ethers prefix -R-O-R--✓✓alkoxy carboxylic acid prefix and suffix-✓✓carboxy- -oic acid carboxylate ion suffix-✓✓-oate esters prefix and suffix -COOR-✓✓alkoxycarbonyl- -oate
a profile about carbocations-✓✓carbocations are highly unstable and reactive species trigonal planar in shape C+ sp2 hybridised a profile about carbanions-✓✓carbanions are highly unstable and reactive species distorted tetrahedral in shape C- is sp3 hybridised homolytic cleavage-✓✓When the bond breaks, each atom gets one electron, and becomes free radicals stability order of free radicals-✓✓methylC=O, alkyl haloes R-X inductive effect-✓✓the polarisation of σ bond caused by the polarisation of adjacent σ bond is called inductive effect inductive effect is inversely proportional to-✓✓number of intervening bonds electron withdrawing groups-✓✓halogens, -NO2, -CN, -COOH, COOR electron donating group-✓✓-CH3, -CH2-CH3, -OH, -NH2, -R, -OR the energy of resonance hybrid-✓✓lower than the energy of any contributing canonical structures resonance energy-✓✓difference between the energy of the resonance hybrid and the energy of the most stable (lowest energy) canonical structure -I effect-✓✓electron withdrawing group effect +I effect-✓✓electron donating group effect resonance effect-✓✓Polarity produced in a molecule from interaction of π-bonds or lone pairs.
+R effect-✓✓the transfer of electrons is away from the substituent group attachéd to the conjugated system +R substituent groups-✓✓halogen, -OH, -OR, OCOR, -NH2, -NHR, -NR2, NHCOR lone pair is necessary -R substituent groups-✓✓-COOH, -CHO, -NO2, -CN, >C=O the presence of alternate single/double bond in an open chain or cyclic system- ✓✓conjured system electromeric effect-✓✓Temporary displacement of π electrons of the multiple bond during reagent attack conditions for electromeric effect-✓✓1. multiple bond
- commando attacking reagent +E effect-✓✓π electrons are transferred to that atom to which the reagent attaches -E effect-✓✓π electrons are transferred to that atom to which reagent doesn't attach when inductive and electromeric effect operates in opposite directions, which predominates?-✓✓electromeric effect which is more electronegative N or O?-✓✓O how to find the most polar bond?-✓✓C-highest EN, that bond is more polar which resonance structure will be more stable?-✓✓the one which has more covalent bond no charge separation everyone is in octet hyperconjugation-✓✓a permanent effect of delocalization of σ electrons of C-H bond by the overlap of a sigma orbital with an empty p orbital hyperconjugation depends on-✓✓greater the number of alkyl carbons attached to a positive carbon atom, greater the hyperconjugation why is (CH3)3C+ more stable than other carbocations?-✓✓due to hyperconjugation common techniques of purification-✓✓sublimation, distillation, crystallisation, differential extraction, chromatography sublimation separates-✓✓sublimable compounds from non sublimable impurities
why alkenes are nucleophiles?-✓✓alkenes are nucleophiles because they have a high electron density in their carbon-carbon double bond 1° & 2° amine are ???? isomers-✓✓functional During the preparation of Mohr's salt solution (Ferrous ammonium sulphate), which of the following acid is added to prevent hydrolysis of Fe2+ ion?-✓✓dilute sulphuric acid The number of σ bonds, π bonds and lone pair of electrons in pyridine, respectively are:-✓✓11,3, Amongst the given options which of the following molecules/ion acts as a Lewis acid?-✓✓BF contains vacant orbital on central atom lewis acid-✓✓electron pair acceptor lewis base-✓✓electron pair donor Huckel's rule-✓✓A molecule is aromatic if it's planar, cyclic, fully conjugated, and has (4n + 2) π-electrons, where n = 0, 1, 2... which power stabilises chlorine?-✓✓Cl has pronounced -I effect than +R effect due to large size difference between carbon and chlorine, also due to high electronegativity of chlorine Predict the order of reactivity of the following four isomers towards SN2 reaction- ✓✓Lesser the steric hinderance on halide carbon, more will be the reactivity of alkyl halide towards SN2 reaction note for ring carbocation, αH is the factor for stability-✓✓ something about chirality-✓✓SN1 reaction yields 1:1 mixture of both enantiomers the product obtained by SN2 reaction of haloalkane having chirality at the reactive site shows inversion of configuration a racemic mixture shows zero optical rotation ZERMATT NOTE PLEASE REVISE - ✓✓ Paper chromatography is an example of-✓✓partition chromatography A tertiary butyl carbocation is more stable than a secondary butyl carbocation because of which of the following?-✓✓hyperconjugation
The most suitable method of separation of 1 : 1 mixture of ortho and para- nitrophenols is-✓✓steam distillation
