List of top Chemistry Questions on Haloalkanes and Haloarenes

The compound with molecular formula C\(_{20}\)H\(_{42}\) is

Identify the product Y in the following reaction sequence \[ C_2H_4 \xrightarrow[(ii)\ AgCN]{(i)\ HBr} X \xrightarrow[\text{Catalyst}]{H_2} Y \]

(i) Explain the nature of the C-X bond. Give an example of a compound having sp³ C-X bonding. (ii) Write chemical equations of the following: (a) Carbylamine reaction (b) Hinsberg reaction.

Describe two methods of preparation of alkyl halides. Also give equations. Explain the following reactions of alkyl halides with examples: (i) Nucleophilic substitution reaction (ii) Elimination reaction.
OR
Write chemical equations of chlorination, nitration, sulphonation, Friedel-Crafts reaction and Wurtz (Fittig) reaction of chlorobenzene.

Write short notes on the following: (i) Freons (ii) Sandmeyer reaction (iii) Friedel Craft acylation of haloarene. (2+1½+1½=5)
OR
What happens when (write chemical equation only): (i) Propene reacts with HI (ii) Ethyl bromide reacts with magnesium in the presence of dry ether (iii) Chlorobenzene is heated with sodium in dry ether (iv) The mixture of chlorobenzene and methyl chloride is heated with sodium in the presence of dry ether (v) Isopropyl alcohol reacts with conc. HCl and ZnCl₂. (1+1+1+1+1=5)

Alkyl chloride reacts with aqueous KOH to form alcohol while in the presence of alcoholic KOH, alkene is obtained as major product. Explain. (2)

Explain the mechanism of bimolecular nucleophilic substitution (S_N2) reaction of alkyl halide.

Write the product of the following reactions along with their mechanism:
i) p-nitrochlorobenzene + NaOH (623 K, 300 atm), then H⁺ → [A]
ii) Chlorobenzene + CH₃COCl (anhydrous AlCl₃) → [B] + [C]
iii) CH₃–CH=C(CH₃)₂ + HBr → [D]
OR
Write short notes on the following: i) D.D.T. ii) Freon iii) Carbon tetrachloride

\( CH_3-CH_2-CH=CH_2 + HBr \xrightarrow{Peroxide} \) product. In this reaction, the main product is —

(i) Explain the mechanism of the Bimolecular Nucleophilic Substitution reaction (S_N2) in a haloalkane and give the order of reactivity of the alkyl halides based on S_N2. (3)
(ii) Name the reagent used in the following reactions: (x) Oxidation of a primary alcohol to an aldehyde. (y) Oxidation of a primary alcohol to a carboxylic acid. (2)
OR
Write the IUPAC names of the following compounds (1+1+1+1+1):
(i) (CH₃)₃C–Cl
(ii) CH₃–CH₂–CH(Br)–CH₃
(iii) 4-F–C₆H₄–COCH₃
(iv) a benzene ring bearing two CH₃ groups and one OH group
(v) CH₃–CH(CH₃)–CH(CH₃)–CH(OH)–C(CH₃)₃

Write the uses of freon. What is its impact on the environment?

Chloroform is oxidised in the presence of sunlight to form

Write the reagent for each of the following reactions:
i) R–OH + …… → R–Cl
ii) R–OH + …… → R–Br
iii) CH₂=CH₂ + …… → BrCH₂–CH₂Br
iv) C₆H₅–CH=CH₂ + …… → C₆H₅–CH₂–CH₂Br

Write the mechanism of the bimolecular nucleophilic substitution reaction (S_N2) of an alkyl halide.

The increasing order of reactivity of the following compounds in \( S_N1 \) reaction is:
A. \( (CH_3)_3CBr \)
B. \( CH_3CH_2CH_2CH_2Br \)
C. \( (CH_3)_2CHCH_2Br \)
D. \( CH_3CH(Br)CH_2CH_3 \)

Reactivity of haloarene increases if an electron withdrawing group (\( -NO_2 \)) is present at the ortho or para position. Explain it with an example and give the reaction mechanism.
OR
Write short notes on the applications of the following: (i) DDT (ii) Freon (iii) Carbon tetrachloride (iv) Chloroform (v) Dichloromethane.

Complete the following chemical reaction:
\( CH_3CH_2CH_2OH \xrightarrow{PBr_3} [A] \xrightarrow[\Delta]{Alc.\ KOH} [B] \)

Write the reaction mechanism of the unimolecular nucleophilic substitution (S_N1) reaction of 2-bromo-2-methylpropane.

Consider the following \[ \begin{aligned} \text{I.} \quad & \text{1-Bromo-1-phenylpropane} \\ \text{II.} \quad & \text{1-Bromo-3-}\mathit{n}\text{-butyl-2-methylbenzene} \end{aligned} \] Bromides I and II are classified respectively as

1-Chlorocyclohexene is an example of

Consider the reaction \(CH_3Cl + NaI \to CH_3I + NaCl\). The name of the reaction and the solvent used to remove \(NaCl\) from the reaction mixture are respectively

In Dettol, chloroxylenol is one component. The IUPAC name of it is

An alkyl halide (X) on reaction with sodium in dry ether gives 2,3-Dimethylbutane. X on reaction with sodium and chlorobenzene in dry ether gives Z as the major product. What is Z?

Observe the following reaction and identify the correct statements about X \[ C_4H_8 \xrightarrow[(ii)\ Zn,H_2O]{(i)\ O_3} Ethanal \] I. It does not exhibit cis/trans isomerism II. It adds water in presence of dilute $H_2SO_4$ to give secondary alcohol III. It is obtained as major product in the reaction of secondary butyl chloride with alcoholic KOH