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| Chemistry 12th Chapter 10 - Alkyl Halides Questions Bank |
Chemistry 2nd Year Chapter 10 - Alkyl Halides Solved MCQs, Important Short Questions and Long Questions Bank
MCQs
Please select the right answer.
1. (CH₃)₃CBr preferably undergoes:
2. 1, 3 – Dibromopropane reacts with metallic zinc to form:
3. 1-bromobutane on reaction with alcoholic potassium hydroxide gives:
4. Acetic acid can be obtained from CH₃MgI by treatment with:
5. Alkyl Halides are:
6. Alkyl magnesium halide (Grignard’s reagent) when hydrolyzed yields:
7. Butane nitrile is formed by reaction of KCₙ with:
8. Carbanions are:
9. Carbocation is a/an:
10. Carbon atom holding halogen in Alkyl halide is:
11. C-X bond is strongest in:
12. Electrophile among the following is:
13. Elimination bimolecular reaction involves:
14. Ethyl alcohol gives Ethyl chloride with the help of:
15. Ethyl bromide when reduced with nascent hydrogen the product will be:
16. Ethyl chloride reacts with alcoholic KOH to give:
17. Ethyl magnesium bromide reacts with water to form:
18. For the reaction C₂H₅OH+ HX → C₂H₅-X + H₂O the order of reactivity of HX is:
19. For which mechanism the first step involved is the same:
20. Grignard reagent is reactive due to:
21. Grignard’s reagent reacts to form alkane with:
22. In SN² mechanism, the hybridization of carbon atom changes from:
23. In primary alkyl halides, the halogen atom is attached to a carbon which is further attached to:
24. In the transition state of SN² mechanism reaction with alkhyl halides, which of the following orbital hybridization is involved:
25. In unimolecular reactions, the reaction completes in:
26. In which two mechanisms, the first step involved is same:
27. In β-elimination reaction, nucleophile attacks on:
28. Iodoethane reacts with sodium in ether, the product formed is:
29. Most reactive Alkyl halide towards SN¹ reaction is:
30. Order and molecularity of SN² reaction of alkyl halide is:
31. Primary alcohol is obtained by treating Grignard’s Regent with:
32. Reaction of C₂H₅MgBr with CO₂ is an example of:
33. Reaction of following with Grignard’s reagent can give primary alcohol:
34. Secondary alcohol is formed when Grignard’s reagent reacts with:
35. Secondary alkyl halides follow
36. SN¹ reaction of Alkyl halides leads to:
37. SN¹ reactions are easily given by:
38. SN² mechanism involves:
39. SN² reaction can be best carried out with:
40. SN² reactions are:
41. Tertiary alcohol is obtained by treating Grignard reagent with:
42. Tertiary alcohols are obtained by treating Grignard’s reagent with:
43. Tetrabomoethane on treatment with alcoholic zinc gives:
44. The alkyl halide is converted into an alcohol directly by:
45. The order of a typical SN² reaction is:
46. The order of a typical SN² reaction is:
47. The reaction of an Alkyl halide with RCOOAg produces:
48. The substances which donates a pair of electron to electrophile are called:
49. Thionyl chloride reacts with alcohol to form:
50. When an alcohol reacts with SOCl₂ an alkyl halide is formed what are two other products:
51. When bromomethane is hydrolyzed by aqueous NaOH solution which ion brings about the first stage of substitution:
52. When Grignard reagent reacts with Epoxide, it forms:
53. Which of the following alkyl halide is the most reactive towards the attacking nucleophile:
54. Which of the following does not give Iodoform test:
55. Which of the following factors does not affect the SN¹ rate is:
56. Which of the following is a Sodium Lead alloy:
57. Which of the following is not a nulceophile:
58. Which of the following is not a Nulceophile?
59. Which of the following reactions is not shown by an alkyl halide:
60. Which of the following reagent cannot be used for preparing alkyl chloride from alcohol:
61. Which one of the following is not a nucleophile:
62. Which one of the following is not associated with SN² mechanism:
63. Which one of the following will have the maximum dipole moment:
64. Which responds positively towards Iodoform test:
65. Which substance is used to convert alcohol to alkyl halide:
66. Which substance is used to convert Grignard’s reagent to alkane:
Short Questions
1. Convert ethanol to get their respective halides by using PCI₃ and PI₅?
2. Define and give one example of each.
i) Nucleophile ii) Leaving group?
3. Explain the order of reactivity of alkyl halides on the basis of bond polarity.
4. Explain the structure and reactivity of Grignard’s reagent.
5. Give the general pattern of reaction of SN¹ mechanism.Why tertiary alkyl halides give this mechanism?
6. Give the general pattern of the reaction of SN²-mexhanism.What is its rate expression?Give examples?
7. Give the mechanism for the addition of Grignard’s reagent at CO₂ ti give carboxylic acids?
8. Give the mechanism for the reaction of formaldehyde with ethyl magnesium bromide?
9. How alkyl halides can be prepared by alcohols? Give two examples.
10. How antiknocking agents are prepared?
11. How compounds with active – H react with G.R to give alkanes?
12. How do we get alkyl nitriles from Grignard’s reagent?
13. How do we get alkyl nitrles from Grignard’s reagent?
14. How do you compare SN¹ and SN² mechanism?
15. How Grignard reagent reacts with epoxides to form alcohol?
16. How is carboxylic acid prepared from Grignard’s reagent?
17. How primary alcohols are produced when ethene epoxide is reacted with Grignard’s reagent?
18. How tetraethyl lead can be prepared from an alkyl halide?
19. How the bond dissociation energy of carbon suggests that alkyl iodides should have maximum reactivity?
20. How the nature of alkyl group changes when alkyl halide is converted to grignanr’s reagent?
21. In tertiary alkyl halides, SN¹ reaction takes place but not SN² reaction. Why?
22. Show the mechanism for the reaction of acetone with Grignard’s reagent?
23. SOCI₂ is the best reagent to get alkyl halides from alcohols.Which solvent is necessary to complete this reaction?
24. What are alkyl halides?Give their general formula and name two monohaloalkanes?
25. What are differences between SN¹ and SN² reactions?
26. What are leaving group and substrate?
27. What are primary and tertiary alkyl halides? Give one example of each.
28. What are primary secondary and tertiary alkyl halides?Give example of each?
29. What are the mecessary conditions to convert alcohols into alkyl halides by using halogen acids?
30. What is an excellent method to prepare alkyl halides?
31. What is difference between Electrophile and Nucleophile?
32. What is difference between Elimination and substitution reactions?
33. What is difference between molecularity and order of reaction?
34. What is Grignard’s reagent? Why dry ether is necessary for the preparation of Grignard’s reagent?
35. What is meant by attacking nucleophile? Give examples.
36. What is the mechanism for the reaction of Grignard’s reagent with acetaldehyde?
37. What is the nature of C-Mg bond in R-Mg-X?
38. What is the order of reactivity of HX with Ethene?
39. What is the role of Carbonium ion for determining SN¹ or SN² mechanism?
40. What is the role of stability of carbonium ion for determining SN¹ or SN² mechanism?
41. What is the role of steric hinderance to decide about SN¹ and SN² mechanisms?
42. What is Wurtz’s synthesis reaction?
43. Which two factors are responsible for reactivity of alkyl halides as compared to alknes?
44. Why tertiary alkyl halides follow SN¹ mechanism and not SN² mechanism?
45. Write down reactions of ethanol with
(i) PBr₃ (ii) PCl₅
Long Questions
1. Define Alkyl Halide. Give three methods to prepare them from Alcohols.
2. Complete the following chemical reactions.
(i) CH₃ CH₂Cl + Na ------->
(ii) CH₃-CH₂-OH+ SOCI₂ ------->
(iii) CH₃-CH₂ - Cl + Na₄Pb ------->
(iv) CH₃ - CH₂ - CI+ KOH(aq) ------->
3. Discuss reactivity of alkyl halides.
4. Discuss two main factors which govern reactivity of halides.
5. Write note on the following terms and give an example in each case.
(i) Substrate (ii) Nucleophile (iii) Electrophile (iv)Leaving group
6. What are SN-reactions? Explain SN¹ reaction in detail.
7. What are SN reaction? Differentiate between SN¹ and SN² reaction?
8. Discuss SN² reactions of alkyl halides in detail.
9. Write a note on SN¹ reactions.
10. Define Nucleophilic substitution reactions and discuss the mechanism of SN¹ reactions
11. What are SN reactions & Explain SN¹ reactions with help of suitable example.
12. Using ethyl bromine how would you prepare
n-Butane, ethene
13. Define elimination reactions and discuss the mechanism of E2 reactions.
14. Write a note on β-elimination reactions.
15. Using ethyl bromide as a starting material how would you prepare:
(i) n-butane (ii) Ethene iii) Ethyl Alcohol (iv) Propanic acid
16. Discuss briefly the two possible mechanisms of β-elimination reactions.
17. Compare E2 and E1 mechanism for the β-Elimination reactions?
18. Write down reaction of CH₃-CH₂-CI with (i) Na (ii) Zn + HCI (iii) Na₄Pb(iv) Mg
19. Write the reactions of the Grignard reagent with the following:
(i) Water (ii) Ammonia (iii) CO₂ (iv) Alcohol
20. How would Grignard reagent reacts with the following: i) Acetaldehyde ii) Acetone iii) Cyanogen Chloride iv) Alcohols
21. What products are formed when the following compounds are treated with ethyl magnesium bromide followed by hydrolysis in the presence of an acid
(i) HCHO (ii) CH₂CHO (iii) (CH₃)₂CO (iv) CICₙ
22. Give reactions of ethyl magnesium bromide with (i) HCHO (iii) CH₃CHO (iii) (CH₃)₂CO (iv) Cl
23. Give reaction of Grignard's reagent with
(i) Alcohol (ii) CO₂ (iii) Acetaldehyde.
24. What products are formed when the following compounds are treated with ethyl magnesium bromide, followed by hydrolysis in the presence of an acid?
(i) Fromaldehyde (ii) CO₂ (iii) Acetaldehyde (iv) Ethyl alcohol
25. How will you make the following conversions:
(i) Acetic acid into propanoic acid
(ii) Acetone into teriary butyl alcohol
26. What is β-Elimination reaction? Differentiate between E1 and E2 elimination reactions. How does ethanol react with
(i) Na (ii) PCI₅ (iii) CH₃MgI (iv) SOCI₂
27. What are Nucleophilic substitution reactions? Explain s² mechanism.
28. What is β- Elimination Reaction? Explain E1 reaction in detail.
29. Write note on the following (i) Classification of Alkyl halides (ii) Wurtz Synthesis.