141.

Ethyl benzene cannot be prepared by

• Wurtz reaction

• Wurtz-Fittig reaction

• Friedel-Craft's reaction

• Clemmensen reduction

Which one of the following is not true for the hydrolysis of t-butyl bromide with aqueous NaOH? 

• Reaction occurs through the S_N1 mechanism

• The intermediate formed is a carbocation

• Rate of the reaction doubles when the concentration of alkali is doubled

• Rate of the reaction doubles when the concentration of t-butyl bromide is doubled 

Following is the substitution reaction in which -CN replaces -Cl.

R-Cl + $\underset{\left(\mathrm{alcoholic}\right)}{\mathrm{KCN}} \underset{∆}{\to }$ R-CN + KCl

To obtaine propanenitrile, R-Cl should be

• chloroethane

• 1-chloropropane

• chloromethane

• 2-chloropropane

Which of the following is not true for S_N1 reaction?

• 3°-alkyl halides generally react through S_N1 reaction

• The rate of the reaction does not depend upon the molar concentration of the nucleophile

• 1°-alkyl halides generally react through S_N1 reaction

• It is favoured by polar solvents

Oil of winter green is

• a carboxylic acid

• an alcohol

• a ketone

• an ester

Match the reactant in Column I with the reaction in Column II.

Column I	Column II
A. Acetic acid	i. Stephen
B. Sodium phenate	ii. Friedel Crafts
C. Methyl cyanide	iii. HVZ
D. Toulene	iv. Kolbe's

• A - iii; B - i; C - iv; D - ii

• A - iv; B - ii; C - iii; D - i

• A - ii; B - iii; C - i; D - iv

• A - iii; B - iv; C - i; D - ii

An incorrect statement with respect to S_N1 and S_N2 mechanisms for alkyl halide is

• A strong nucleophile in an aprotic solvent increases the rate or favours S_N2 reaction.

• Competing reaction for an S_N2 reaction is rearrangement.

• S_N1 reactions can be catalysed by some Lewis acids.

• A weak nucleophile and a protic solvent increases the rate or favours S_N1 reaction.

The hydrolysis of optically active 2-bromobutane with aqueous NaOH result in the formation of

• (+) butan -2-ol

• (-) butan-2-ol

• (±) butan-1-ol

• (±) butan-2-ol

Predict the product 'C' in the following series of reactions:

CH₃-COOH $\stackrel{{\mathrm{PCl}}_5}{\to } \mathrm{A} \underset{\mathrm{Anhy}. {\mathrm{AlCl}}_3}{\overset{{\mathrm{C}}_6{\mathrm{H}}_6}{\to }} \mathrm{B} \stackrel{{\mathrm{CH}}_3\mathrm{MgBr}}{\to } \mathrm{C}$

• 

• CH₃CH(OH)C₆H₅

• CH₃CH(OH)C₂H₅

• (CH₃)₂C(OH)C₆H₅

In Grignard reagent the carbon-magnesium bond is:

• electrovalent

• covalent

• dative

• hydrogen bonding