ECAT Pre Engineering Chemistry Chapter 21 MCQ Test With Answer

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

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

Grignard's reagent on treatment with carbonyl compounds yield

• Pheonol A
• Alcohol B
• Alkane C
• None of these 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

A set of compounds in which reactivity of halogen atom in the ascending order is

• Chlorobenzene, vinyl chloride, chloroethane A
• Chloroethane, chlorobenzene, vinyl chloride B
• Vinyl chloride,chlorobenzene chloroethane C
• Vinyl chloride, chloroethane,chlorobenzene D

Organic compounds containing halogen atom are called:

• R---OH A
• R----X B
• R----NH₂ C
• R----COH 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

Most reactive halide towards S_N1 reaction is

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

S_N1 reaction of alkylhalides leads to

• Retention of configuration A
• Recemisation B
• Inversion of configuration C
• None of these D

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

Which of the followings is not a nulceophile

• OH^- A
• NH₃ B
• C₂H₅O^- C
• Br₂ D

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

• Ca A
• Na B
• Mg C
• Zn 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

To get DDT, chlorobenzene has to react with one of the following compound in the presence of conc.H₂SO₄

• Trichloroethane A
• Dichloroacetone B
• Dichloroacetaldehyde C
• Trichloroacetealdehyde D

Which of the following compounds gives trichoromethane on distilling with bleaching power?

• Methanal A
• Phenol B
• Ethanol C
• methanol D

Which one of the following is not a nucleophile

• H₂O A
• H₂S B
• BF₃ C
• NH₃ 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

A reaction in which an atom or a group of atoms replaces an atom or a group of atoms in the molecule of a substance is known as

• Addition reaction A
• Condensation reaction B
• Elimination reaction C
• Substitution reaction D

The reaction between primary amine-chloroform and alcoholic caustic potash is called

• Wurtz reaction A
• Frankland reaction B
• Cannizzaro's reaction C
• Carbylamine reaction 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 reactive :

• High A
• Medium B
• Less C
• Least D

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

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

Elimination bimolecular reactions involve:

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

Which is a weak nucleophile

• OH^- A
• Br^- B
• NH₃ C
• CI^- D

Which of the following is a nucleophile

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

SN₂reactions can be best carried out with:

• Prl. alkyl halide A
• Sec. Alkyl halide B
• Ter. Alkyl halide C
• All of three 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

Grignad 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 above D