ECAT Pre Engineering Chemistry Chapter 21 MCQ Test With Answer

Which of the following with aqueous KOH will give acetaldehyde?

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

Which is a good nucleophile?

• F^-1 A
• Cl^-1 B
• Be^-1 C
• I^-1 D

Action of Zn with alkyl halides in the presence of an inert solvent forms higher alkanes. This reaction is known as

• Wurtz reaction A
• Frankland's reaction B
• Cannizaro reaction C
• Kalobe's reaction 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

Elimination bimolecular reactions involve:

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

Which one of the following is not a nucleophile

• H₂O A
• H₂S B
• BF₃ C
• NH₃ D

Ethyl alcohol gives ethyl chloride with the help of

• SOCl₂ A
• NaCl B
• Cl₂ C
• KCl D

Grignard's reagent on treatment with dry CO₂and HCI yields

• Ester A
• Alcohol B
• Carboxylic acid C
• Aldehyde D

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

• 
  A
• 
  B
• 
  C
• 
  D

When chloroform is boiled with NaOH, it gives

• Formic acid A
• Trihydroxymethane B
• Acetylene C
• Sodium formate D

Ethyl chloride on treatment with aqueous alkali gives

• Ethane A
• Ethene B
• Ethanal C
• Ethanol 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

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

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

Dehydrohalogenation of alkyl halides give

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

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

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

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 these D

The alkyl halide molecule on which a nucleophile attacks is called

• Substrate A
• Subsituent B
• Substituted C
• All of these D

Electronegativity order of alkyl halides is:

• Rl > RBr > RCl > RF A
• Rbr > RCl > RF >Rl B
• RCl > RF >Rl > RBr C
• RF >Ri > RBr >RII D

When CO₂ is made to react with ethyl megnesium iodine, followed by hydrolysis, the product formed is:

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

Alkyl halides react with lithium dialkyl copper reagents to give

• Alkenes A
• Alkyl copper halides B
• Alkanes C
• Alkenyl halides D

Iodoethane reacts with sodium in ether, the product formed is

• Pentene A
• Propyne B
• Butene C
• Butane 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

Which of the following is a nucleophile

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

SN₂ reaction has order of reaction :

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

In primary alkyl halides, the halogen atom is attached to a carbon which attached to how many carbon atoms?

• Two A
• Three B
• One C
• Four D

The most reactive compound for electrophilic nitration will be

• Benzyl chloride A
• Benzoic acid B
• Nitrobenzene C
• Chlorobenzene D

Which responds to +ve iodoform test?

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

Tertiary alkyl halides are practically inert to substitution by S_N2 mechanism because of

• Onsolubility A
• Instability B
• Inductive effect C
• Steric hindrance D