April 20, 2020

13. Hydrocarbons


2 & 3 Marks
1. What are Hydrocarbons?
2. What are Saturated hydrocarbons? Give examples.
3. What are Unsaturated hydrocarbons? Give examples.
4. What are Alkanes? Give the General formula.
5. Name Hydrocarbons according to IUPAC system of nomenclature.
6. Give the IUPAC name for the following Alkane.
    a) CH3 – CH – CH2 – CH2 – CH – CH3              b) CH3 – CH – CH – CH – CH2 – CH2 – CH2 – CH3
                     |                                |                                               |         |        |
                    CH2                         CH2                                         CH3  CH3  CH2
                     |                                |                                                                  |
                    CH3                          CH3                                                           CH3
7. Draw the Structural formula for 3-Ethyl-2,3-dimethyl pentane
8. Draw the Structural formula for 4,5-Diethyl -3,4,5-trimethyl octane
9. Write the Structures of folowing Alkanes.             1) 2,3-Dimethyl-6-(2-methyl propyl) decane
      2) 5-(2-Ethyl butyl)-3,3-dimethyldecane              3) 5-(1,2-Dimethyl propyl)-2-methylnonane
10. What is Hydrogenation? Give example.
11. What happen when a mixture Hydrogen gas with Propene gas is passed over Platinum catalyst at room temperature?
12. What happen when a mixture Hydrogen gas with Prop-1-yne gas is passed over Platinum catalyst at room temperature?
13. What is Sabatier - Sendersens reaction?
14. What happen when a mixture Hydrogen gas with Ethene gas is passed over Ni catalyst at 298 K?
15. What is Decarboxylation? Give example.
16. What is Soda lime? What is its use?
17. What happen when a mixture of Sodium acetate and Soda lime is heated?
18. How will you Prepare Propane from a Sodium salt of fatty acid?
19. What is Kolbe’s Electrolytic method?
20. Is it possible to prepare Methane by Kolbe’s Electrolytic method?
21. Name a method suitable for preparing Symmetrical Alkanes. Prepare Butane by it.
22. What happen when Sodium or Potassium salt of carboxylic acid is electrolyzed?
23. What happen when Sodium acetate is electrolyzed?
24. List the Reducing agents used to obtain Nascent hydrogen for reduction of Alkyl halides to Alkanes.
25. Convert Chloro propane to Propane by reduction with Nascent hydrogen.
26. What is Wurtz reaction? What is its Use?
27. How will you convert Ethyl chloride in to i) Ethane        ii) n-Butane?
28. Name the process to prepare Higher alkanes with even number of C - atoms. Prepare 1-Butane by it.
29. What is Corey- House Mechanism?
30. How Methane can be prepared from Grignard reagent?
31. Water destroys Grignard reagents. Why?
32. What are Conformations?
33. What are Conformers?
34. What is Skew Conformation? Or What are Skew forms?
35. Draw the Newman projection formula for Ethane.
36. Write the chemical equations for combustion of Propane.
37. Write down the Combustion reaction of Propane whose ΔH° = - 2220 kJ
38. Why Ethane is produced in Chlorination of Methane?
39. What is Aromatisation?
40. How Aromatisation occurs?
41. What happen when n-Hexane is passed over Cr2O3 supported on Alumina at 873 K?
42. How Toluene can be prepared by Aromatisation?
43. What happen when Methane reacts with steam at 1273 K in the presence of Nickel?
44. What is Steam reforming process?
45. Define Pyrolysis.
46. What is Cracking?
47. What is Isomerisation? Give its importance?
48. What are Alkenes? Give the General formula.
49. Alkenes are also known as Olefins. Why?
50. Write the IUPAC names for the following Alkenes.
      i) CH3 – CH – CH = CH – CH3                                      ii) CH3 – C = CH – CH2 – CH2– CH3
                       |                                                                                          |
                     CH3                                                                                      CH2
                                                                                                                     |
                                                                                                                CH3

51. Draw the Structures for the following Aalkenes.
      i) 6-Bromo-2,3-dimethyl-2-hexane                                   ii) 5 – Bromo-4-chloro-1-heptene
      iii) 2,5-Methyl-4-octane                                                    iv) 4-Methyl-2-pentene
52. Explain Structural Isomerism in Alkene.
53. Draw Geometrical isomers of 2-Butane
54. Determine whether each of the following Alkenes can exist in cis-trans isomers?
      a) 1-Chloro propene                                                          b) 2-Chloro propene
 55. Draw cis-trans Isomers for the following compounds
       a) 2-chloro-2-butane                                                         b) CH3 – CCl = CH – CH2 – CH3
56. How can you Prepare Alkene from Alcohol?
57. What happen when an Alcohol is heated at 430 - 440 K with excess of concentrated Sulphuric acid?
58. What happen when Ethanol is heated at 430 - 440 K with excess of concentrated Sulphuric acid?
59. What happen when Ethanol is heated at 623K - 723K with Alumina / Al2O3?
60. How can you Prepare Alkenes from Alkynes?
61. How can you Prepare cis-Alkene from Alkyne?
62. How can you prepare cis-2-Butene from 2-Butyne?
63. How can you Prepare trans-Alkene from Alkyne?
64. How can you prepare trans-2-Butene from 2-Butyne?
65. What is Lindlar’s catalyst?
                                                               Lindlar Catalyst
66. Complete the following: 2-Butyne --------------------->
67. How can you Prepare Alkene from Halo alkanes?
68. How can you prepare Prop-1-ene from 1-Bromopropane?
69. What are vicinal dihalides? Give examples.
70. How can you Prepare Alkene from vicinal dihalogen derivative of alkanes or vicinal dihalides?
71. What happens when vicinal dihalides are warmed with granulated Zinc in Methanol?
72. Starting from1,2-Dibromoethane how will you prepare Ethene?
                                                                    Zn / C2H5OH
73. Complete the following: CH2 – CH2 --------------------->
                                               |           |
                                              Br        Br
74. How Propene is prepared form 1,2-Dichloro propane?
75. How Ethene is Prepared by Kolbe’s electrolytic method? Or
      What happens when an aqueous solution of Potassium succinate is electrolyzed?
76. Alkenes are more reactive than Alkanes. Why?
77. What happens in the Addition of Hydrogen to Alkenes / Hydrogenation of Alkenes?
78. What is Catalytic hydrogenation?
79. What happens in the Addition of Halogens / Halogenation of Alkenes?
80. What happens when Alkene is treated with Halogens like Chlorine or Bromine?
81. What happens when Alkene is treated with Iodine?
                                                                         I2
82. Complete the following: CH2 = CH2 ------------>
83. Give the Tests for Alkene.
84. Give the characteristic Tests for Unsaturated compounds.
85. Suggest a simple chemical test to Distinguish Propane and Propene.
86. State Markovnikoff’s rule.
87. Explain Markownikoff's rule with suitable example.
88. What happens in the Addition of Water to Alkenes / Hydration of Alkenes?
89. What happens in the Addition of Hydrohalides to Alkenes / Hydrohalogenation of Alkenes?
90. What happens in the Addition of HBr to Symmetrical alkene?
91. What happens in the Addition HBr to Unsymmetrical alkene?
92. What is Peroxide Effect?
93. State Anti-Markovnikoff’s Rule.
94. What is Kharasch Addition?
95. What happens in the Addition of Sulphuric acid to Alkenes?
96. What is Baeyer’s reagent?
97. What happens when Alkenes react with cold dilute alkaline KMnO4 solution (Baeyer’s Reagent)?
98. What happens when Ethylene is passed through cold dilute alkaline Potassium permanganate?
99. What happens when Alkenes react with acidified KMnO4 solution?
100. What happens when Isobutylene is treated with acidified Potassium permanganate?
101. What is Ozonolysis? What is its Use?
102. What happens when Ethene react with Ozone?
103. What happens when Prop-1-ene react with Ozone?
104. How Ozone reacts with 2-Methyl propene?
105. What is a Polymer?
106. What is Polymerisation?
107. What are the Uses of Alkenes?
108. What are Alkynes? Give the General formula.
109. How can you Prepare Alkynes from Alkenes?
110. How can you Prepare Propyne from its corresponding Alkene?
111. How can you Prepare Acetylene from 1,2-Dibromoethane?
112. What is gem dihalide? Give examples.
113. How can you Prepare Alkyne from gem dihalides
114. How is Propyne prepared from an Alkyene dihalide?
115. How is Prop-1-yne prepared from 1,1-Dichloropropane?
116. How can you Prepare Alkynes from Electrolysis of Salts of Unsaturated Dicarboxylic Acids.
117. How Acetylene / Ethyne is Prepared by Kolbe’s electrolytic method? Or What happens when an aqueous solution of Potassium maleate or Sodium fumarate is electrolyzed?
118. How is Ethyne manufactured from Calcium carbide? Or How is Ethyne Industrially prepared?
                                                             H2O
119. Complete the following: CaC2 ----------->
120. How will you Distinguish 1–Butyne and 2–Butyne?
121. How will you Distinguish Terminal Alkynes and Nonterminal Alkynes?
122. Describe Addition reactions of Alkynes.
123. What happens in the Addition of Hydrogen to Alkyne?
124. What happens in the Addition of Hydrogen to Acetylene?
125 What happens in the Addition of Halogens to Alkyne?
126. What happens in the Addition of Br2 in CCl4 to Acetylene?
127. What happens in the Addition of Br2 in CCl4 to Propyne?
128. What happens in the Addition of Hydrogen Halides to Alkyne?
129. What happens in the Addition of Hydrogen Halides to Symmetrical Alkyne?
130. What happens in the Addition of HCl to 2-Butyne?
131. What happens in the Addition of Hydrogen Halides to UnsymmetricalAlkyne?
132. What happens in the Addition of HBr to 1-Butyne?
133. What happens in the Addition of Water to Alkyne?
134. What happens in the Addition of Water to Ethyne? Or How is Acetylene hydrated?
135. What happens in the Addition of Water to Propyne?
136. What is the action of Ozone on Acetylene?
137. What is the action of Ozone on Propyne?
138. Explain briefly on Linear Polymerisation of Alkynes.
139. Explain briefly on Cyclic Polymerisation of Alkynes.
140. What happens when Acetylene is passed through red-hot tube?
141. What are the Uses of Alkynes?
                                                                Pt                   H2
142. Complete: CH ≡ C – CH3 + H2 -----------> ? ------------> ?
143. Classify the Aromatic hydrocarbons depending upon number of rings present in it.
144. Give examples for Polycyclic aromatic hydrocarbon (PAH).
145. Calculate the Number of rings present in C18H12.
146 What is Huckel’s rule?
147. How does Huckel rule help to decide the Aromatic character of a compound? Or  
        Explain Aromaticity.
148. Using Huckel’s rule Show that Benzene is an Aromatic compound.
149. Using Huckel’s rule Prove Naphthalene is an Aromatic compound.
150. Using Huckel’s rule Show that Anthracene is an Aromatic compound.
151. Using Huckel’s rule Confirm Cyclo penta diene is not an Aromatic compound.
152. Using Huckel’s rule Show that Cyclo octatetraene is not an Aromatic compound.
153. Using Huckel’s rule explain Cyclo propenyl cation is an Aromatic compound.
154. Give Evidences for Cyclic structure of Benzene.
155. How is Benzene Industriallly Prepared from Coal tar?
156. How can you Prepare Benzene from Acetylene? Or Convert Ethyne to Benzene and name the process.
157. What happens when Sodium benzoate in heated with Soda lime?
158. How is Benzene prepared from Phenol?
159. What happens when Phenol vapours are passed over Zinc dust?
160. How Benzene can be prepared by Grignard Reagent?
161. What is Wurtz – Fittig Reaction?
162. What happens when a solution of Bromo benzene and Iodo methane in dry Ether is treated with  
      metallic Sodium?
163. What is Friedel Craft’s Reaction?
164. What happens when Benzene is treated with Methyl chloride in the presence of anhydrous AlCl3?
165. Electrophilic substitution reaction occurs in Benzene – Explain. Or Why Benzene undergoes
        Electrophilic substitution reaction where as Alkenes undergoes Addition reaction?
166. What is a Nitrating mixture?
167. What happens when Benzene is heated at 330 K with a Nitrating mixture?
168. What happens when Benzene reacts with Halogens in the presence of Lewis acid such as FeCl3, FeBr3 or AlCl3?
169. What happens when Benzene reacts with Cl2 in the presence of FeCl3?
170. What happens when Benzene reacts with Br2 in the presence of FeBr3?
171. What happens when Benzene reacts with Fluorine?
172. What happens when Benzene reacts with fuming Sulphuric acid?
173. What is Friedel Craft’s Alkylation?
174. What happens when Benzene is treated with an Alkyl halide in the presence of AlCl3?
175. Starting from Benzene how will you prepare Toluene?
176. What is Friedel Craft’s Acylation?
177. What happens when Benzene is treated with Acetyl chloride in the presence of AlCl3?
178. Starting from Benzene how will you prepare Acetophenone?
179. Write a note on Hydrogenation of benzene.
180. Write a note on Vapour – phase Oxidation.
181. What is Birch reduction?
182. What are Activating groups and Deactivating groups? Give examples for each.
183. Toluene undergoes Nitration easily than Benzene. Why?
184. Suggest the route for the preparation of 3-Chloro nitrobenzene from Benzene.
185. Suggest the route for the preparation of 4-Chlorotoluene from Benzene.
186. Suggest the route for the preparation of Bromo benzene from Benzene.
187. Suggest the route for the preparation of m-dinitro benzene from Benzene.

5 Marks
1. Classify Hydrocarbons according to Nature of bond between the carbon atoms.
2. Write the Structural formula and Carbon skeleton formula for all possible Chain isomers of Pentane, C5H12.
3. Write the Structural formula and Carbon skeleton formula for all possible Chain isomers of C6H14 (Hexane).
4. Describe various methods of Preparing Alkanes. Or How can be Alkanes prepared?
5. Describe the Conformations of Ethane.
6. Explain the Stabilities of various conformations of Ethane.
7. Describe the Conformers of n-Butane.
8. Explain the relative Stabilities of various conformers of n-Butane.
9. Describe the Mechanism of reaction of Methane with Chlorine in the presence of light or when heated.
10. Describe Isomerism in Alkene.
11. Draw the Structure and write down the IUPAC name for the Isomerism exhibited by the molecular formulae     i) C5H12 – Pentene (3 Isomers)                    ii) C6H14 – Hexene (5 Isomers)
12. Describe Geometrical Isomerism Or Describe cis-trans Isomerism.
13. Describe General methods of preparation of Alkenes.
14. Describe Addition reactions of Alkenes.
15. Discuss the Mechanism of Addition of HBr to Propene.
16. Discuss the Mechanism of Addition of HBr to 3-Methyl-1-butene.
17. Discuss the Mechanism of Addition of HBr to Propene in the presence of organic peroxide.
18. Describe Recycling plastics.
19. Give IUPAC names for the following compounds
      1) CH3 – CH = CH – CH = CH – C ≡ C – CH3             3) (CH3)3 C – C ≡ C – CH (CH3)2
                       C2H5   CH3
                        |            |                                                           4) Ethyl isopropyl acetylene
       2) CH3 – C       C – C ≡ C – CH3                               
                        |            |                                                           5) CH ≡ C – C ≡ C – C ≡ CH
                       CH3     H
20. Describe General Methods of Preparation of Alkynes.
21. Describe Chemical properties of Alkynes.
22. Deduce Acidic hydrogen in Alkynes.
23. Explain briefly on Polymerisation reaction of Alkynes.
24. Write all possible Isomers for an aromatic benzenoid compound having the molecular formula C8H10.
25.  Write all possible Isomers for a Mono substituted aromatic benzenoid compound having the molecular formula C9H12.
26. Describe the Structure of Benzene.
27. Describe the Preparation of Benzene.
28. Discuss the Laboratory Methods of Preparing Benzene.
29. Discuss the Laboratory Methods of Preparing Toluene.
30. Describe Electrophilic substitutions reactions in Benzene.
31. Describe the Mechanism of Electrophilic substitutions reactions.
32. Describe the Mechanism of Nitration of Benzene.
33. Describe the Mechanism of Halogenation of Benzene.
34. Describe the Mechanism of Sulphonation of Benzene.
35. Describe the Mechanism of Fridel Craft's Alkylation of Benzene.
36. Describe the Mechanism of Fridel Craft's Acylation of Benzene.
37. Discuss Addition reaction in Benzene.
38. Predict the directive influence of substituents on mono substituted benzene.
39. Write short notes on ortho, para directors in Aromatic electrophilic substitution reactions.
40. Write short notes on meta directors in Aromatic electrophilic substitution reactions.
41. Explain the Toxicity and Carcinogenic nature of Aromatic hydrocarbons.

Problems
1. An organic compound (A) on Ozonolysis gives only Acetaldehyde. (A) reacts with Br2 / CCl4 to give compound (B). Identify the compounds (A) and (B). Write the IUPAC name of (A) and (B). Give the Geomatrical isomers of (A).
2. An organic compund (A) C2H4 decolourises Bromine water. (A) on reaction with Chlorine gives (B). A reacts with HBr to give (C). Identify (A), (B) and (C). Explain the reactions.
3. Write the products A & B for the following reaction.
                                         Alcoholic KOH           Alcoholic KOH
    Cl – CH2 – CH2 – Cl --------------------->  (A) ---------------------> (B)
                                                  – HCl                             – HCl
4. Identify the compound A, B, C and D in the following series of reactions
      CH3 – CH2 – Br
         alc. KOH
   
  
      
   ▼
            Cl2 / CCl4
      A ------------->    B
   │           │  
         i) O3                     NaNH2
          ii) Zn / H2
   ▼           ▼
      C                         D
5. An alkyl halide with molecular formula C6H13Br on dehydro halogenation gave two isomeric alkenes X and Y with molecular formula C6H12. On reductive Ozonolysis, X and Y gave four compounds CH3COCH3, CH3CHO, CH3CH2CHO and (CH3)2 CHCHO. Find the Alkyl halide.
6. CH3 – CH (CH3) – CH (OH) – CH3 
          
           H+ / Heat
                                       HBr
    (A) Major product -----------> (B) Major product
    Identify A and B.

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