ECAT Pre Engineering Chemistry Chapter 21 MCQ Test With Answer

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

Hydrolysis of Grignard's reagent gives:

• Alcohol A
• Halide B
• Alkyl C
• Alkane 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

Which of the following alkyl halides is used as a mathylating agent

• CH₂H₅l A
• CH₃l B
• C₂H₅Pr C
• C₂H₅Cl D

The order of reactivity for a given halogen in Grignard's reagent is:

• CH₃X > C₂H₅X > C₃H₄X > C₄H₄X A
• C₂H₅X > C₃H₇X > C₄H₅X > CH₄X B
• C₃H₇X > C₄H₇X > CH₃X > C₂H₅X C
• C₄H₄X > C₃H₇X > C₂H₅X > CH₄X D

SN₂ reaction has order of reaction :

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

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

Ethyl chloride on treatment with aqueous alkali gives

• Ethane A
• Ethene B
• Ethanal C
• Ethanol 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

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

which one of the following is not a nucleophile?

• H₂O A
• H₂S B
• BF₃ C
• NH₃ D

The final product formed by distilling ethyl alcohol with excess of Cl₂ and Ca(OH)₂is

• CH₃CHO A
• CCl₃CHO B
• CHCl₃ C
• (CH₃)₂O 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

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

Reation of which with Grignard's reagent gives primary alcohol:

• Formaldehyde A
• Aldehyde B
• Ketones C
• Acetone D

Iodoethane reacts with sodium in ether, the product formed is

• Pentene A
• Propyne B
• Butene C
• Butane D

Primary carbon attaches with other hydrogen atoms directly:

• One A
• Two B
• Three C
• At least one or more than it D

Alkyl halides on treatment with metallic Na give

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

The alkyl halide molecule on which a nucleophile attacks is called

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

Cyanoform is ________ acid in nature than the chloroform. The missing word is

• Stronger A
• Weaker B
• Amphoteric C
• Neutral 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

Grignard reagent is prepared by the reaction of magnesium metal with alkyl halide in the presence of

• Alcohol A
• Water B
• Suephuric acid C
• Dry ether D

Any other aldehyde except formaldehyde on reaction with Grignard's will produce

• Secondary alcohol A
• Primary alcohol B
• Tertiary alcohol C
• Aromatic alcohol D

Which is a good nucleophile?

• F^-1 A
• Cl^-1 B
• Be^-1 C
• I^-1 D

C₆H₆Cl₆can be obtained from

• HCl and Benzene A
• Cl₂and Benzene and AlCl₃ B
• Cl₂and Benzene in diffused light C
• NaOCl and Benzene D

Which reaction is example of nucleophilic substitution

• 
  A
• 
  B
• 
  C
• 
  D

Alkyl halides are reactive :

• High A
• Medium B
• Less C
• Least 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

Ethyl bromide is formed by the reaction of HBr with

• Ethane A
• Ethene B
• Ethyne C
• Propane D

By simply reacting Grignand's reagent with water we get

• An alkane A
• Higher alkane B
• An alkene C
• An alkyne D