ECAT Pre Engineering Chemistry Chapter 21 MCQ Test With Answer

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 reaction is example of nucleophilic substitution

• 
  A
• 
  B
• 
  C
• 
  D

• Electronphilic substitution A
• Electrophilic addition B
• Free radical substitution C
• Nuclephilic substitution D

Hydrolysis of Grignard's reagent gives:

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

Alkyle halides can be prepared by treating halogen acids with

• Ethane A
• Ethanol B
• Ethene and ethanol C
• Aldehyde 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

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

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

Grignard reagent is not prepared in aqueous medium but prepared in ether medium because

• The reagent is highly reactive in ether A
• The reagent does not react with water B
• The reagent becomes inactive in water C
• The reagent reacts with water D

The reaction of an alkyl halide with RCOOAg produces

• Ester A
• Ether B
• Aldehyde C
• Ketone 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

The reaction between primary amine-chloroform and alcoholic caustic potash is called

• Wurtz reaction A
• Frankland reaction B
• Cannizzaro's reaction C
• Carbylamine reaction 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

To get DDT, chlorobenzene has to react with one of the following compound in the presence of conc.H₂SO₄

• Trichloroethane A
• Dichloroacetone B
• Dichloroacetaldehyde C
• Trichloroacetealdehyde 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

By reaction Grignard's reagent with the HCHO we get

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

which one of the following is not a nucleophile?

• H₂O A
• H₂S B
• BF₃ C
• NH₃ D

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

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

How many monochlorobutanes will be possible on chlorination of n-butane?

• 1 A
• 2 B
• 3 C
• 5 D

An electrophile may be

• Positive A
• Negative B
• Neutral C
• Both c and a 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

Alcohol can be prepared from Grignard's reagent with an aldehyde: If we start with formaldehyde the product alcohol with be

• Primary A
• Secondary B
• Territory C
• Aromatic D

Which one of the following is not a nucleophile

• H₂O A
• H₂S B
• BF₃ C
• NH₃ D

C₆H₆Cl₆can be obtained from

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

Grignard reagent is reactive due to :

• The presence of halogen atom A
• The presence of Mg atom B
• The polarity of C - Mg bond C
• None of them D

SN₂reactions can be best carried out with:

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

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

• Formaldehyde A
• Aldehyde B
• Ketones C
• Acetone 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

Ethyl chloride on treatment with aqueous alkali gives

• Ethane A
• Ethene B
• Ethanal C
• Ethanol D

When primary amine reacts with chloroform in ethanolic KOH, then the product is

• An isocyanide A
• An aldehyde B
• A cyanide C
• An alcohol D