ECAT Pre Engineering Chemistry Chapter 21 MCQ Test With Answer

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

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

Alkanes may be prepared by the reaction of alkyl halides with

• Alcohol A
• Carboxylic acid B
• Grignard reagents C
• None of these 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

Which of the following compounds on oxidation gives benzoic acid?

• Chlorophenol A
• Chlorotoluene B
• Chlorobenzene C
• Benzyl chloride D

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

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

Grignard's reagent on treatment with carbonyl compounds yield

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

• Electrophilic substitution A
• Free radical reduction B
• Isomerisation C
• Nucleophilic substitution D

General formula of alkyl halide is:

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

E₁mechanism is generally shown by

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

Gammexane is

• Chlorobenzene A
• Benzyl chloride B
• Brommobenzene C
• Benzene hexachloride D

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

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

Which of the following with aqueous KOH will give acetaldehyde?

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

S_N1 reaction of alkylhalides leads to

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

Steps in SN , reactions are:

• One A
• Two B
• Three C
• Four 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

When ethyl iodide and n-propyl iodide are allowed to react with sodium metal in ether, the number of alkanes that could be produced is

• Only one A
• Two alkanes B
• Three alkanes C
• Four alkanes 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

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 of the following compounds will form a hydrocarbon on reaction with Grignard reagent

• A ketone A
• An aldehyde B
• An ether C
• Water D

Alkyl halides react with Mg in dry ether to form

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

Reaction of Griganard's reagent with CO₂gives:

• Aldehyde A
• Pri-alcohol B
• Sec-alcohal C
• Carboxylic acid D

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

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

Alkyl halides on treatment with aqueous KOH give

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

Alkyl halides ae 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

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

If carbon dioxide is bubbled through solution of Grignard's reagent in ether and the resultant product is reacted with hydrochloric acid, it gives

• An alkane A
• Al alcohol B
• A carboxylic acid C
• An aldehyde D

Carbon atom holding halogen in aryl halides is

• sp²-hybridesed A
• sp³-hybridesed B
• sp-hybridesed C
• sp³d-hybridesed D

Benzene hexachloride is used as

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

C- X bond is strong in

• CH₃Cl A
• CH₃Br B
• CH₃F C
• CH₃I D