ECAT Pre Engineering Chemistry Chapter 21 MCQ Test With Answer for Chemistry chapter 21 (Alkyl Halides)

The reactivity order of alkyl halides for a particular alkyl group is:

• F >Cl>Br>I A
• Cl>Br>F>l B
• l>Br>Cl>F C
• Br>l>Cl>F D

Grignad 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 above 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

An electrophile may be

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

Which of the following is a nucleophile

• OH A
• CH(CH₃)₃ B
• CH₃⁺ C
• CH₃CH₂CH₃ D

The elimination of hydrogen halide from adjacent carbon atoms is called

• Dehydrogenation A
• Hydrogenation B
• Dehydrohalogenation C
• Hydrohalogenation D

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

When alkyl halide is heated with aqueous solution of ammonia at 100°C the major product is

• Primary amine A
• Secondary amine B
• Tertiary amine C
• Mixture of amines and salt D

Hydrolysis of Grignard's reagent yields

• Alcohol A
• Aldyhyde B
• Ester C
• Alkane D

Grignard's reagent on treatment with dry CO₂and HCI yields

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

With the increase in size of halogen atom the reactivity of an alkyl halide

• Increases A
• Decreases B
• Remain constant C
• None of these D

Alkyl halides react with lithium dialkyl copper reagents to give

• Alkenes A
• Alkyl copper halides B
• Alkanes C
• Alkenyl halides 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

Which of the followings is not a nulceophile

• OH^- A
• NH₃ B
• C₂H₅O^- C
• Br₂ D

Which reaction is example of nucleophilic substitution

• 
  A
• 
  B
• 
  C
• 
  D

The reactivity order of alkyl halides for a paricular alkyl group is

• Fluoride > chloride > bromide > iodide A
• Chloride > bromide > fluoride > iodide B
• Iodide > bromide > chloride > fluoride C
• Bromide > iodide > chloride > fluoride 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

SN₂reactions can be best carried out with:

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

Hydrolysis of Grignard's reagent gives:

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

E₁mechanism is generally shown by

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

The alkyl halide molecule on which a nucleophile attacks is called

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

DDT is formed from

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

Reaction of Griganard's reagent with CO₂gives:

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

• Primary alkyl halide A
• Secondary alkyl halide B
• Tertiary alkyl halide C
• None of these 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 is not a nucleophile?

• H₂O A
• H₂S B
• BF₃ C
• NH₃ D

Tetrabromoethane on treatment with alcoholic zinc gives

• Ethylbromide A
• Ethane B
• Ethene C
• Ethyne 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