ECAT Pre Engineering Chemistry Chapter 21 MCQ Test With Answer

By reaction Grignard's reagent with the HCHO we get

• 1° - alcohol A
• 2° - alcohol B
• 3° - alcohol C
• All of these 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

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

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

• 
  A
• 
  B
• 
  C
• 
  D

Which one of the following is not a nucleophile

• H₂O A
• H₂S B
• BF₃ C
• NH₃ D

When carbon dioxide is passed through the R - Mg - X is produced

• Any carboxylic acid A
• Propanoic acid B
• Propanedioic acid C
• None of these D

The reactivity order of alkyl halides for a paricular alkyl group is

• Fluoride > chloride > bromide > iodide A
• Chloride > bromide > fluoride > iodide B
• Iodide > bromide > chloride > fluoride C
• Bromide > iodide > chloride > fluoride D

The order of reactivity of an alkyl halide (R-X) for a particular alkyl group is

• Iodide > bromide > chloride A
• Chloride > bromide > iodide B
• Bromide > chloride > iodide C
• Bromide > iodide > chloride D

Hydrolysis of Grignard's reagent yields

• Alcohol A
• Aldyhyde B
• Ester C
• Alkane 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

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

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

• 2-bromo-3-methylbutane A
• 3-methyl-2-bromobutane B
• 2-methyl-3-bromobutane C
• All of these D

Allyl chloride on dehydrochlorination gives

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

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

• Benzamide A
• Nitrobenzene B
• Aniline C
• Chloroaminobenzene 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

Which of the following reacts with chloroform and base to form phenyl isocynaide?

• Nitrobenzene A
• Phenol B
• Chlorobenzene C
• Aniline 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

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

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

The elimination of hydrogen halide from adjacent carbon atoms is called

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

Both E₁and E₂mechanism can be shown by

• 1° - RX A
• 2° - RX B
• 3° - RX C
• None of these D

C₆H₆Cl₆can be obtained from

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

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

Alkyl halides react with Mg in dry ether to form

• Magnesium halide A
• Grignard's reagent B
• Alkene C
• Alkyne D

The most reactive compound for electrophilic nitration will be

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

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

Thre rate of S_N2 reaction depends upon the

• Concentration of alkyl halides A
• Concentration of nucleophile B
• Concentration of alkyl halides and nucleophile C
• None of the above D

Alkyl halides on treatment with aqueous KOH give

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

Benzene hexachloride is used as

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