ECAT Pre Engineering Chemistry Chapter 21 MCQ Test With Answer

When ethyl iodide and n-propyl iodide are allowed to react with sodium metal in ether, the number of alkanes that could be produced is

• Only one A
• Two alkanes B
• Three alkanes C
• Four alkanes 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 a good leaving group B
• They have an electrophilic carbon and a bad leaving group C
• They have a nucleophilic carbon and a good leaving group 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

Which of the following chlorocompounds is heat easily hydrolysed by hydorxide ion to give the product indicated

• 
  A
• 
  B
• 
  C
• 
  D

Benzene hexachloride is used as

• Dye A
• Antimaterial drug B
• Antibiotic C
• Insecticide D

Which one of the following in mainly responsible for depletion of ozone layer?

• Methane A
• Carbon dioxide B
• Water C
• chloroflurocarbons D

Hydrolysis of Grignard's reagent yields

• Alcohol A
• Aldyhyde B
• Ester C
• Alkane D

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

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

CFCs undergo homolytic fission by uv light in the stratosphere which radical could result from this irradiations of CHCICF₂Cl.

• CHF Cl C FCl A
• CH Cl CF₂Cl B
• CHF CF₂Cl C
• C FCl CF₂Cl D

Alkyl halides on treatment with aqueous KOH give

• Phenol A
• Alcohol B
• Aldehyde C
• Ketone D

Gammexane is

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

Which of the followings is not a nulceophile

• OH^- A
• NH₃ B
• C₂H₅O^- C
• Br₂ D

Dehydrohalogenation of alkyl halides give

• Alkanes A
• Alkenes B
• Alkynes C
• Alkdehyde 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

Alkyl halides ae considered to be very reactive compounds towards nucleophiles because

• They have an electrophilic carbon A
• They have an electrophilic carbon and a good leaving group B
• They have an electrophilic carbon and a bad leaving group C
• They have a nucleophilic carbon and a good leaving group D

1-Chlorobutane on reaction with alcoholic potash gives

• But 1-ene A
• Butan-1-ol B
• But-2-ene C
• Butan-2-ol 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

• NH₃ HCl A
• KCN in C₂H₅OH NaOH B
• KCN in C₂H₅OH HCl C
• HCN NaOH D

Which is a weak nucleophile

• OH^- A
• Br^- B
• NH₃ C
• CI^- 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

Elimination bimolecular reactions involve:

• First order Kinetics A
• Third order kinetics B
• Zero order kinetics C

Steps in SN , reactions are:

• One A
• Two B
• Three C
• Four D

Reactivity of alkyl halides with magnisium is of the order:

• Rl > RBr> RCl > RF A
• RBr > RCl >RF > Rl B
• RCL > RF > Rl > RBr C
• RF >RI >RBr > RII D

Elimination bimolecular reactions usually obey

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

The elimination of hydrogen halide from adjacent carbon atoms is called

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

DDT is formed from

• Benzene and Chlorobenzene A
• Chloral and Chlorobenzene B
• Chloral and Benzene C
• Chlorobenzene and chlorine D

General formula of alkyl halide is:

• R----X A
• R----OH B
• R------COH C
• R------COOH D

Grignard's reagent was prepared in:

• 1900 A
• 1910 B
• 1920 C
• 1930 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

The reaction of an alkyl halide with RCOOAg produces

• Ester A
• Ether B
• Aldehyde C
• Ketone D