ECAT Pre Engineering Chemistry Chapter 21 MCQ Test With Answer

The chloroform reacts with NaOH to give

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

SN₂ reaction has order of reaction :

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

Which one of the following will have the maximum dipole moment

• CH₃F A
• CH₃Cl B
• CH₃Br C
• CH₃l 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

Organic compounds containing halogen atom are called:

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

Which responds to +ve iodoform test?

• Butanol-1 A
• Butan-1-al B
• Butanol-2 C
• 2-pentanone D

Elimination bimolecular reactions involve:

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

Benzene hexachloride is used as

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

Which one of the following is not a nuclelphile

• H₂O A
• H₂S B
• BF₃ C
• NH₃ D

Which is a good nucleophile?

• F^-1 A
• Cl^-1 B
• Be^-1 C
• I^-1 D

SN₂reactions can be best carried out with:

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

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

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

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

• Stronger A
• Weaker B
• Amphoteric C
• Neutral D

Hydrolysis of Grignard's reagent yields

• Alcohol A
• Aldyhyde B
• Ester C
• Alkane 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

When formaldehyde is added to Grignard reagent we get

• Aldehyde A
• Acetone B
• Primary alcohol C
• Secondary alcohol D

Alkyl halides on treatment with aqueous KOH give

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

Best medhod of preparation of alkyl halide from alcohals is by its reaction with:

• HX A
• SOCl₂ B
• Px₅ and PX₃ C
• All D

Which represents nucleophilic aromatic substitution reaction?

• Reaction of benzene with Cl₂in sunlight A
• Benzyl bromide hydrolysis with water B
• Reaction of NaOH with dintrofluoro benzene C
• Sulphonation of benzene D

The reaction of an alkyl halide with RCOOAg produces

• Ester A
• Ether B
• Aldehyde C
• Ketone D

1-Chlorobutane on reaction with alcoholic potash gives

• But 1-ene A
• Butan-1-ol B
• But-2-ene C
• Butan-2-ol D

• Electrophilic addition A
• Electrophilic substitution B
• Free radical substitution C
• Nuclophilic addition 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 halide among the following is used as methylating agent?

• CH₃l A
• C₂H₅Cl B
• C₂H₅Br C
• C₆H₅Cl D

which one of the following is not a nucleophile?

• H₂O A
• H₂S B
• BF₃ C
• NH₃ D

Hydrolysis of Grignard's reagent gives:

• Alcohol A
• Halide B
• Alkyl C
• Alkane 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

2-Bromopentane is heated with potassium ethoxide in ethanol . The major product obtained is

• 2-Ethoxypentane A
• Pent-1-ene B
• cis-Pent-2-ene C
• trans-Pent-2-ene D