Give reason qs Flashcards
Words, reaction fails in the case of tert alkyl halides why
This is because they undercover the Hydro halogenation in the presence of sodium metal instead of undergoing wurtz reaction
Out of cyclo hex chloride and chlorobenzene, which one is more reactive and nucleophilic substitution reactionary and why?
Out of chlorobenzene and cyclohexyl chloride, which one is more reactive towards nuclephic substitution reaction and why?
Cyclohexyl chloride is more reactive than chlorobenzene towards nucleophilic substitution reactions. Dre to resonance the C-Cl bond in chlorobenzene acquires partial double bond character which makes te substitution of chlorine more difficult in chlorobenzene than in cyclohexyl chloride where the Claus has pure single bond character.
Give one chemical test to distinguish between ethyl bromide and phenyl bromide
Hydrolysis of CH,Br with aqueous KOH followed by acidification with dil. HNO, and subsequent treatment with AgNO, gives light yellow ppt. of AgBr whereas C,H,Br does not give thís test.
2016)
(i) C-Cl bond length in chlorobenzene is shorter than C—Cl bond length in CH,-Cl
(i) In chlorobenzene, C-Cl bond acquires partial double bond character while in methyl chloride, C-0 bond has pure single bond character. As a result C-Cl bond in chlorobenzene is shorter than meth chloride.
Su1 reactions are accompanied by racemisation in optically active alkyl halides.
Carbocations are intermediate in Syl reactions. Carbocations being sp? hybridised are planar species therefore, attack of nucleophile on it can occur from both front and rear with almos equates gie a racemic mixture.
p-nitrochlorobenzene undergoes nucleophilic substitution faster than chlorobenzene. Explain giving the resonating structures as well.
(i) In p-nitrochlorobenzene a carbanion intermediate is formed. This is stabilised by resonance
The -I effect of nitro group further stabilises the intermediate. Hence, p-nitrochlorobenzene reacts faster than chlorobenzene.
lodoform is obtained by reaction of acetone with hypoiodite ion but not iodide ion.
Hypoiodite ion can act as an oxidising agent while iodide ion does not.
Benzyl chloride is highly reactive towards the Syl reaction.
Benzyl chloride is highly reactive towards the Sy reaction because the intermediate benzyl carbocation formed in slowest step is stabilized through resonance.
