ECAT Pre Engineering Chemistry Chapter 21 MCQ Test With Answer

Most reactive halide towards S_N1 reaction is

• n-Butyl chloride A
• sec-Butyl chloride B
• tert-Butyl choride C
• Allyl chloride D

Ethyl bromide on treatment with alcoholic KOH gives

• Ethylene A
• Ethanol B
• Acetic Acid C
• Ethane D

When alkyl halide is heated with aqueous solution of ammonia at 100°C the major product is

• Primary amine A
• Secondary amine B
• Tertiary amine C
• Mixture of amines and salt D

Which responds to +ve iodoform test?

• Butanol-1 A
• Butan-1-al B
• Butanol-2 C
• 2-pentanone D

The rate of E₁reaction depends upon

• The concentration of substrate A
• The concentration of nucleophile B
• THe concentration of substrate as well as nucleophile C
• None of the above D

The reaction of 4-bromobenzyl chloride with NaCN in ethanol leads to

• 4-Bromobenzyl cyanide A
• 4-Cyanobenzyl chloride B
• 4-Cyanobenzyle cyanide C
• 4-Bromo 2-cyanobenzyl chloride D

When alkyl halides are heated with aqueous solution of ammonia at about 100°C, amines are formed. This reaction is known as

• Williamsons synthesis A
• GHoffmans reaction B
• Wurtz reaction C
• Clemensen reaction D

Steps in SN , reactions are:

• One A
• Two B
• Three C
• Four D

The compounds or species in search of electrons are called

• Elctrophiles A
• Nucleophile B
• Nitrities C
• Bases D

Elimination bimolecular reactions usually obey

• First order kinetics A
• Second order kinetics B
• Third order kinetics C
• Zero order kinetics D

Gammexane is

• Chlorobenzene A
• Benzyl chloride B
• Brommobenzene C
• Benzene hexachloride D

The elimination of hydrogen halide from adjacent carbon atoms is called

• Dehydrogenation A
• Hydrogenation B
• Dehydrohalogenation C
• Hydrohalogenation D

• Electronphilic substitution A
• Electrophilic addition B
• Free radical substitution C
• Nuclephilic substitution D

Ammonia like water also reacts with Grignard's reagent to give

• Alkane A
• Alkene B
• Alkyne C
• Amide D

Alcohol can be prepared from Grignard's reagent with an aldehyde: If we start with formaldehyde the product alcohol with be

• Primary A
• Secondary B
• Territory C
• Aromatic D

For the carbylamine reaction we need hot alc.KOH and

• Any amin and chloroform A
• Chloroform and Ag powder B
• A primary amine and chloroform C
• A mono alkyl amine and trichlorom-ethane D

Dehydrohalogenation of alkyl halides give

• Alkanes A
• Alkenes B
• Alkynes C
• Alkdehyde D

What happens when CCl₄is treated with AgNO₃solution?

• NO₂will be evolved A
• A white ppt. of AgCl will form B
• CCl₄will dissolve in AgNO₃solution C
• Nothing will happen D

Alkyl halides are considered to be very reactive compounds towards nucleophiles, because:

• They have an electrophilic carbon A
• They have an electrophilic carbon and good living gorup B
• They have an electrophilic carbon and bad living group C
• They have an nucleophilic carbon and good living gorup D

Grignard's reagent on treatment with chloramine give

• Acetamide A
• Primary amice B
• Secondary amice C
• Urea D

• Primary alkyl halide A
• Secondary alkyl halide B
• Tertiary alkyl halide C
• None of these D

When metallic sodium in ether is heated with ethyl chloride, which alkane is formed

• Propane A
• Ethane B
• Iso-butane C
• N-butane D

Grignard reagent is reactive due to :

• The presence of halogen atom A
• The presence of Mg atom B
• The polarity of C - Mg bond C
• None of them D

Which of the following is a nucleophile

• OH A
• CH(CH₃)₃ B
• CH₃⁺ C
• CH₃CH₂CH₃ D

Which of the following reagent cannot be used for preparing alkyl chloride from alcohol?

• HCl + anhyd. Zncl₂ A
• NaCl B
• PCl₅ C
• SOCl₂ D

If Grignard reagent is allowed to react with another alkyl halide the main product is

• An alkane A
• Cyclo alkane B
• Alkyne C
• An alkene D

Which of the following compounds could be prepared by reacting bromoethane with KCN and then reducing the product

• CH₃CH₃ A
• CH₃CH₂NH₂ B
• CH₃CH₂CH₂NH₂ C
• CH₃CH₂CH₃ D

Alkyle magnesium halides are known as

• Simon-smith reagent A
• Tollen's reagent B
• Grignard's reagent C
• Barford's reagent D

Reaction of ethylamine with chloroform in alcoholic KOH produces

• CH₃OH A
• CH₃NC B
• C₂H₅NC C
• C₂H₅CN D

Chlorobenzene on heating with aqueous NH₃under pressure in the presence of cuprous chloride gives

• Benzamide A
• Nitrobenzene B
• Aniline C
• Chloroaminobenzene D