22575.If ‘n’ represents total number of asymmetric carbon atoms in a compound, the possible number of optical isomers of the compound is
2n
n2
2n
2n + 2
22576.A solution of (+)–2–chloro–2–phenylethane in toluene racemises slowly in the presence of small amount of SbCl5, due to the formation of
Carbanion
Carbene
Free–radical
Carbocation
22577.Chlorobenzene is formed by reaction of chlorine with benzene in the presence of AlCl3. Which of the following species attacks the benzene ring in this reaction?
Cl–
Cl+
AlCl3
[AlCl4]–
22578.An incorrect statement with respect to SN1 and SN2 mechanisms for alkyl halide is
A strong nucleophile in an aprotic solvent increases the rate or favours SN2 reaction.
Competing reaction for an SN2 reaction is rearrangement.
SN1 reactions can be catalysed by some Lewis acids.
A weak nucleophile and a protic solvent increases the rate or favours SN1 reaction.
is22580.The arrangement of following compounds
i. bromomethane
ii. bromoform
iii. chloromethane
iv. dibromomethane
in the increasing order of their boiling point is
i. bromomethane
ii. bromoform
iii. chloromethane
iv. dibromomethane
in the increasing order of their boiling point is
iii < i < iv < ii
iv < iii < i < ii
ii < iii < i < iv
i < ii < iii < iv
22581.Match the reactant in Column – I with the reaction in Column – II.
| Column – I | Column – II | ||
|---|---|---|---|
| (i) | Acetic acid | (a) | Stephen |
| (ii) | Sodium phenate | (b) | Friedel – Crafts |
| (iii) | Methyl cyanide | (c) | HVZ |
| (iv) | Toluene | (d) | Kolbe’s |
i – c, ii – a, iii – d, iv – b
i – d, ii – b, iii – c, iv – a
i – b, ii – c, iii – a, iv – d
i – c, ii – d, iii – a, iv – b
22582.Alkaline hydrolysis of which among the following compounds leads to the formation of a racemate?
1–Bromo–1–phenylethane
1–Chloro–3–methylbutane
Bromoethane
1–Chloropropane
22583.IUPAC name of the compound 
is
is
1 – Bromo but – 2 – ene
2 – Bromo – 2 – butane
Bromobutane
1 – Bromo but – 3 – ene
22584.A solution of ( – ) – 1 – chloro–1– phenylethane in toluene racemises slowly in the presence of a small amount of SbCl5, due to the formation of :
carbanion
carbene
carbocation
free radical
22585.Consider the reaction
CH3CH2CH2Br + NaCN → CH3CH2CH2CN + NaBr
This reaction will be the fastest in
Ethanol
Methanol
N, N´–dimethylformamide (DMF)
Water
22586.Replacement of Cl of Chlorobenzene to give phenol requires drastic conditions, but Cl of 2, 4–dinitrochlorobenene is readily replaced. This is because
–NO2 group makes the ring electron rich at ortho and para positions
–NO2 group withdraws electrons from meta position
–NO2 donate electrons at meta position
–NO2 withdraws electrons from ortho and para positions
22587.The compound which is NOT formed when a mixture of n–butyl bromide and ethyl bromide treated with sodium metal in presence of dry ether is
Butane
Octane
Hexane
Ethane
22588.A primary alkyl halide would prefer to undergo ______.
SN1 reaction
SN2 reaction
α–Elimination
Racemisation
22589.The synthesis of alkyl fluorides is best accomplished by
Free radical fluorination
Sandmeyer's reaction
Finkelstein reaction
Swarts reaction