ECAT Pre Engineering Chemistry Chapter 21 MCQ Test With Answer

Organic compounds containing halogen atom are called:

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

When an alcohol reacts with SOCI₂an alkyl halide is formed. What are two other products

• SO₂and HCI A
• SI₂and H₂O B
• HCI and H₂O C
• H₂S and HCI 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

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

• Formaldehyde A
• Aldehyde B
• Ketones C
• Acetone 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

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

Iodoethane reacts with sodium in ether, the product formed is

• Pentene A
• Propyne B
• Butene C
• Butane D

Grignard's reagent on treatment with dry CO₂and HCI yields

• Ester A
• Alcohol B
• Carboxylic acid C
• Aldehyde D

Dehydrohalogenation of alkyl halides give

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

Alkyl halides react with Mg in dry ether to form

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

• Condensation A
• Electrophilic substitution B
• Free radical substitution C
• Nucleophilic substitution 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

What is the total number of different chloroethanes of formula C₂H_6-nCl_npossible (n may be 1 to 6)

• 6 A
• 8 B
• 9 C
• 10 D

Which halide among the following is used as methylating agent?

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

E₁mechanism is generally shown by

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

Alkyle magnesium halides are known as

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

The final product formed by distilling ethyl alcohol with excess of Cl₂ and Ca(OH)₂is

• CH₃CHO A
• CCl₃CHO B
• CHCl₃ C
• (CH₃)₂O D

An electrophile may be

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

Aryl halides are less reactive towards nucleophilic substitution reactions as compared to alkyl halides due to

• The formation of less stable carbonium ion A
• Resonance stabilization B
• Larger carbon-halogen bond C
• The inductive effect D

The alkyl halide molecule on which a nucleophile attacks is called

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

Which one of the following is not a nuclelphile

• H₂O A
• H₂S B
• BF₃ C
• NH₃ D

Metal used in the preparation of Grignard's reagent is:

• Ca A
• Na B
• Mg C
• Zn D

Allyl chloride on dehydrochlorination gives

• Propadiene A
• Propylene B
• Allyl alcohol C
• Acetone D

Halogens on treating with silver salts of acids give

• Alcohol A
• Ester B
• Phenol C
• Alkyl halide D

By reaction Grignard's reagent with the HCHO we get

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

SN₂ reaction has order of reaction :

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