ECAT Pre Engineering Chemistry Chapter 21 MCQ Test With Answer

1, 3-Dibromopropane reacts with metallic zinc to form

• Propene A
• Propane B
• Cyclopropane C
• Hexane D

Alkyl halides on treatment with metallic Na give

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

Most reactive halide towards S_N1 reaction is

• n-Butyl chloride A
• sec-Butyl chloride B
• tert-Butyl choride C
• Allyl chloride D

The alkyl halide molecule on which a nucleophile attacks is called

• Substrate A
• Subsituent B
• Substituted C
• All of these 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

A reaction in which an atom or a group of atoms replaces an atom or a group of atoms in the molecule of a substance is known as

• Addition reaction A
• Condensation reaction B
• Elimination reaction C
• Substitution reaction D

What is the total number of different chloroethanes, formula C₂H_6-nCl_n, where n can be any integer from 1 to 4

• 4 A
• 6 B
• 7 C
• 8 D

Reaction of ethylamine with chloroform in alcoholic KOH produces

• CH₃OH A
• CH₃NC B
• C₂H₅NC C
• C₂H₅CN D

Grignard's reagent on treatment with carbonyl compounds yield

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

Reduction of alkyl halides give

• Alkanes A
• Alkenes B
• Ketones C
• Ether D

Alkyl halides are reactive :

• High A
• Medium B
• Less C
• Least D

C- X bond is strong in

• CH₃Cl A
• CH₃Br B
• CH₃F C
• CH₃I D

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

Elimination bimolecular reactions usually obey

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

Any other aldehyde except formaldehyde on reaction with Grignard's will produce

• Secondary alcohol A
• Primary alcohol B
• Tertiary alcohol C
• Aromatic alcohol D

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

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

DDT is formed from

• Benzene and Chlorobenzene A
• Chloral and Chlorobenzene B
• Chloral and Benzene C
• Chlorobenzene and chlorine D

Which one of the following is not a nuclelphile

• H₂O A
• H₂S B
• BF₃ C
• NH₃ D

Ethyl alcohol gives ethyl chloride with the help of

• SOCl₂ A
• NaCl B
• Cl₂ C
• KCl D

When chloroform is boiled with NaOH, it gives

• Formic acid A
• Trihydroxymethane B
• Acetylene C
• Sodium formate 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

If ketone reacts with Grignard's reagent, it also produces alcohol, But it will be a

• primary alcohol A
• Secondary alcohol B
• Tertiary alcohol C
• Aromatic alcohol D

Which of the following alkyl halides is used as a mathylating agent

• CH₂H₅l A
• CH₃l B
• C₂H₅Pr C
• C₂H₅Cl D

Action of Zn with alkyl halides in the presence of an inert solvent forms higher alkanes. This reaction is known as

• Wurtz reaction A
• Frankland's reaction B
• Cannizaro reaction C
• Kalobe's reaction D

When formaldehyde is added to Grignard reagent we get

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

C₆H₆Cl₆can be obtained from

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

Catalyst in the reaction ROH + SOCl₂-------> RCL+SO₂+HCl is:

• ZnCl₂ A
• Pyridine B
• H₂SO₄ C
• Either D

What happens when CCl₄is treated with AgNO₃solution?

• NO₂will be evolved A
• A white ppt. of AgCl will form B
• CCl₄will dissolve in AgNO₃solution C
• Nothing will happen D