ECAT Pre Engineering Chemistry Chapter 21 MCQ Test With Answer

When formaldehyde is added to Grignard reagent we get

• Aldehyde A
• Acetone B
• Primary alcohol C
• Secondary alcohol D

Alkanes may be prepared by the reaction of alkyl halides with

• Alcohol A
• Carboxylic acid B
• Grignard reagents C
• None of these D

Replacement of Cl of Chlorobenzene to give phenol requires drastic conditions but chlorine of 2, 4-Dinitrochlorobenzene is readily replaced because

• NO₂makes the electron rich ring at ortho and para positions A
• NO₂withdraws electrons at metaposition B
• NO₂donate electrons at m-position C
• NO₂withdraws electrons at ortho and para position D

• Condensation A
• Electrophilic substitution B
• Free radical substitution C
• Nucleophilic substitution D

If carbon dioxide is bubbled through solution of Grignard's reagent in ether and the resultant product is reacted with hydrochloric acid, it gives

• An alkane A
• Al alcohol B
• A carboxylic acid C
• An aldehyde 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

On warming with silver powder,chloroform is converted into

• Acetylene A
• Hexachloroethane B
• 1,1,2,2-tetrachloroethane C
• ethylene 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

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

Allyl chloride on dehydrochlorination gives

• Propadiene A
• Propylene B
• Allyl alcohol C
• Acetone D

Which of the following undergoes uncleophilic substitution exclusively by S_N1 mechanism?

• Benzyl chloride A
• Ethyl chloride B
• Chlorobenzene C
• Isopropyl choride D

The elimination of hydrogen halide from adjacent carbon atoms is called

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

which one of the following is not a nucleophile?

• H₂O A
• H₂S B
• BF₃ C
• NH₃ D

When CO₂is made to react with ethyl magnesium iodide, followed by acid hydrolysis, the product formed is

• Propane A
• Propanoic acid B
• Propanal C
• Propanol D

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

• Benzamide A
• Nitrobenzene B
• Aniline C
• Chloroaminobenzene 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

The reactivity order of alkyl halides for a particular alkyl group is:

• F >Cl>Br>I A
• Cl>Br>F>l B
• l>Br>Cl>F C
• Br>l>Cl>F D

The reaction of alcohol with SOCI₂in the presence of pyridine as catalyst gives

• Acids A
• Acid chloride B
• Alkyl halide C
• Benzene D

Ethyl bromide on treatment with alcoholic KOH gives

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

The alkyl halide is converted into an alcohol by

• Addition A
• Substitution B
• Dehydrohalogenation C
• Elimination D

Grignard's reagent on treatment with chloramine give

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

With the increase in size of halogen atom the reactivity of an alkyl halide

• Increases A
• Decreases B
• Remain constant C
• None of these D

Metal used in the preparation of Grignard's reagent is:

• Ca A
• Na B
• Mg C
• Zn D

When primary amine reacts with chloroform in ethanolic KOH, then the product is

• An isocyanide A
• An aldehyde B
• A cyanide C
• An alcohol D

Butanenitrile is formed by reaction of KCN with

• Propyl alcohol A
• Butyl chloride B
• Butyl alcohol C
• Propyl Chloride D

In which of the following reactions is the inorganic reagent acting as a nucleophile

• 
  A
• 
  B
• 
  C
• 
  D

Which of the following with aqueous KOH will give acetaldehyde?

• 1, 2-Dichloroethane A
• 1,1-Dichloroethane B
• Chloracetic acid C
• Ethyl chloride D

For which mechanisms, the first step involved is the same:

• E₁ and E₂ A
• E₂and SN₂ B
• E₂ and E₁ C
• E1 and SN₁ D

Unpleasant smell of carbylamine is obtained when chloroform and alcoholic KOH are heated with

• Any aromatic amine A
• Any primary amine B
• Any amine C
• Any aliphatic amine D

What is the total number of different chloroethanes, formula C₂H_6-nCl_n, where n can be any integer from 1 to 4

• 4 A
• 6 B
• 7 C
• 8 D