Chemistry_Class-12_DPP-1_Ch-6_Haloalkanes and Haloarenes. 1 / 25 1. Which of the following is an optically active compound? A) 1 – Butanol B) 1 – propanol C) 2 – chlorbutane D) 4 – Hydroxy heptane 2 / 25 2 – Bromopentane is heated with potassium ethoxide in ethanol. The major product obtained is? A) 2 – ethoxypentane B) pentene C) trans pent - 2- ene D) cis – pent- 2- ene 3 / 25 3. CH3 CH2 CH (Cl) CH3 obtained by chlorination on n- butane, will be A) 𝒍−𝒇𝒐𝒓𝒎 B) 𝒅−𝒇𝒐𝒓𝒎 C) 𝒎𝒆𝒔𝒐 𝒇𝒐𝒓𝒎 D) Racemic mixture 4 / 25 4. An organic compound A (C4H9Cl) on reaction with Na /dry ether gives a hydrocarbon which on monochlorination gives only one chloro derivative ,then A is A) tert – butyl chloride B) sec- butyl chloride C) isobuthyl chloride D) n-butyl chloride 5 / 25 A) B) C) D) 6 / 25 6. Reactivity order of halides for dehydrohalogenation is A) R – F > R – Cl > R – Br > R – I B) R – I > R – Br > R – Cl > R – F C) R – I > R – Cl > R – Br > R – F D) R – F > R – I > R – Br > R – Cl 7 / 25 7. In a SN2 substitution reaction which one of the following has the highest relative rate ? \textbf{Question:} In an \textit{SN}$_2$ substitution reaction, which one of the following has the highest relative rate? Given the reaction: \[ \text{R - Br} + \text{Cl}^- \xrightarrow{\text{DMF}} \text{R - Cl} + \text{Br}^- \] \textbf{Options:} \begin{enumerate} \item Primary halide with Br$^-$ as leaving group \item Secondary halide with Br$^-$ as leaving group \item Tertiary halide with Br$^-$ as leaving group \item Primary halide with Cl$^-$ as leaving group \end{enumerate} \textit{[AIPMT 2008]} A) B) C) D) 8 / 25 8. Which of the following is least reactive in a nucleophilic substitution reaction ? A) B) C) D) 9 / 25 9. Which of the following undergoes nucleophilic substitution exclusively by SN1 mechanism? A) Ethyl chloride B) Isopropyl chloride C) Chlorbenzene D) chlorophenylmethane 10 / 25 10. Which of the following reactions is an example of nucleophilic substitution reaction ? A) RX + KOH ----> ROH + KX B) 2RX + 2Na ----> R – R + 2NaX C) RX + H2 ----> RH + HX D) RX + Mg ----> RMgX 11 / 25 11. Which of the following reactions is an example of nucleophilic substitution reaction? A) B) C) D) 12 / 25 Consider the reactions: (CH₃)₂CH - CH₂Br c. H₂O ⟶ (CH₃)₂CH - CH₂OCH₃ + HBr (CH₃)₂CH - CH₂Br c. H₂O ⟶ (CH₃)₂CH - CH₂OCH₂ + Br⁻ The mechanisms of reactions (i) and (ii) are respectively : A) B) C) D) 13 / 25 13. In which of the following compounds, the C–Cl bond ionisation shall give most stable carbonium ion ? A) B) C) D) 14 / 25 14. A) (I), (III) and (IV) only B) (I) and (II) only C) (IV) only D) (III) and (IV) only 15 / 25 15. Which of the following statements is not correct for a nucleophile ? A) Nucleophile is a Lewis acid B) Ammonia is a nucleophile C) Nucleophiles attack low e– density sites D) Nucleophiles are not electron seeking 16 / 25 16. In an SN1 reaction on chiral centers there is : A) 100 % racemization B) inversion more than retention leading to partial racemization C) 100 % retention D)100 % inversion 17 / 25 17. A) (a) is substitution, (b) and (c) are addition reactions. B) (a) and (b) are elimination reactions and (c) is addition reaction. C) (a) is elimination, (b) is substitution and (c) is addition reaction. D) (a) is elimination, (b) and (c) are substitution reaction. 18 / 25 18. A) X = 1-Butyne ; y = 2-Hexyne B) X = 1-Butyne ; y = 3-Hexyne C) X = 2-Butyne ; y = 3-Hexyne D) X = 2-Butyne ; 2 = 2-Hexyne 19 / 25 19. A) ) water B) ethanol C) methanol D) N,N’-dimethylformaide (DMF) 20 / 25 20. Which of the following can be used as the halide component for Freidel–Crafts reaction? A) Isopropyl chloride B) Chlorobenzene C) Bromobenzene D) Chloroethene 21 / 25 21. Which of the following compounds shall not produce propene by reaction with HBr followed by elimination or direct only elimination reaction ? A) B) C) D) 22 / 25 22. Which one of the following nitro-compounds does not react with nitrous acid A) B) C) D) 23 / 25 23. The correct statement regarding electrophile is : A) Electrophile is a negatively charged species and can form a bond by accepting a pair of electrons from a nucleophile B) Electrophile is a negatively charged species and can form a bond by accepting a pair of electrons from another electrophile C) Electrophiles are generally neutral species and can form a bond by accepting a pair of electrons from a nucleophile D) Electrophile can be either neutral or positively charged species and can form a bond by accepting a pair of electrons from a nucleophile 24 / 25 24. The compound A on treatment with Na gives B, and with PCl5 gives C, B and C react together to give diethyl ether. A, B and C are in the order A) B) C) D) 25 / 25 25. Among the following the reaction that produce through an electrophilic substitution is \ce{NH3 + H2O -> NH4+ + OH-} A) B) C) D) Your score isThe average score is 10% 0% Exit
