ECAT Pre Engineering Chemistry Chapter 21 MCQ Test With Answer

The most reactive compound for electrophilic nitration will be

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

Grignard's reagent was prepared in:

• 1900 A
• 1910 B
• 1920 C
• 1930 D

Alkyl halides on treatment with metallic Na give

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

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

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

On warming with silver powder,chloroform is converted into

• Acetylene A
• Hexachloroethane B
• 1,1,2,2-tetrachloroethane C
• ethylene D

Which one of the following is not a nuclelphile

• H₂O A
• H₂S B
• BF₃ C
• NH₃ D

Alkyle magnesium halides are known as

• Simon-smith reagent A
• Tollen's reagent B
• Grignard's reagent C
• Barford's reagent D

SN₂reactions can be best carried out with:

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

Replacement of Cl of Chlorobenzene to give phenol requires drastic conditions but chlorine of 2, 4-Dinitrochlorobenzene is readily replaced because

• NO₂makes the electron rich ring at ortho and para positions A
• NO₂withdraws electrons at metaposition B
• NO₂donate electrons at m-position C
• NO₂withdraws electrons at ortho and para position 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

SN2 reaction can be best carried out with

• Primary alkyl halides A
• Secondary alkyl halides B
• Tertiary alkyl halides C
• All the three D

When CO₂is made to react with ethyl magnesium iodide, followed by acid hydrolysis, the product formed is

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

Hydrolysis of Grignard's reagent gives:

• Alcohol A
• Halide B
• Alkyl C
• Alkane D

Ethyl bromide is formed by the reaction of HBr with

• Ethane A
• Ethene B
• Ethyne C
• Propane 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

Alkyl halides on treatment with Zn and HCI gives

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

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

• Nitrobenzene A
• Phenol B
• Chlorobenzene C
• Aniline D

SN₂ reaction has order of reaction :

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

Which of the following is a nucleophile

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

Which halide among the following is used as methylating agent?

• CH₃l A
• C₂H₅Cl B
• C₂H₅Br C
• C₆H₅Cl 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

Which is a good nucleophile?

• F^-1 A
• Cl^-1 B
• Be^-1 C
• I^-1 D

The chloroform reacts with NaOH to give

• CH₃COONa A
• Sodium oxalate B
• CH₃OH C
• HCOONa D

The general formula of alkyl halides is

• C_nH_2nX A
• C_nH_2n-1X B
• C_nH_2n+1X C
• C_nH_2n-2X D

Which of the following does not give iodoform test?

• Ethanol A
• Ethanal B
• Acetophenone C
• Bezophenone 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

A carbon atom carrying a postitive charge and attached to three other atoms of groups is called

• Caronium ion A
• Carbanion B
• Oconium ion C
• Carba ion 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

Primary carbon attaches with other hydrogen atoms directly:

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