Answer: Question 26. What are vicinal dihalides? how will you convert ethyl chloride in to – Answer: Question 21. Assertion : tert-Butyl bromide undergoes Wurtz reaction to give 2, 2, 3, 3-tetramethylbutane. Answer: As a result, benzene undergoes electrophilic substitution reactions easily and nucleophilic substitution with difficulty. (b) Citric acid Answer: The percentage of s-character of sp hybrid orbital (50%) is more than sp2 hybrid orbital ofalkenes (33%) and sp3 hybrid orbital of alkanes (25%). Answer: 1. Answer: It is made up of polypropylene whereas others are made of PET (Polyethylene terephthalate). Wurtz-fittig reaction helps to prepare compounds ………… What are all the conditions for aromaticity? Answer: Let us consider the directive influence of phenolic group. Explain the structure of benzene. (A) reacts with Br2 /CCl4 to give compound (B). How will you prepare propane from a sodium salt of fatty acid? (d) Ethanol (c) LiAlH4 1. 1. Why benzene undergoes electrophilic substitution reaction whereas alkenes undergoes addition reaction? Question 12. Answer: When tertiary alkyl halide reacts with primary alkoxide, elimination dominates and succeeds over substitution to form an alkene. Draw Newman and Sawhorse projections for the eclipsed and staggered conformations of ethane. (c) (A)is correct but (R) is wrong. On reductive ozonolysis, X and Y gave four compounds CH3COCH3. (b) Wurtz reaction How will you distinguish 1 – butyene and 2 – butyne? (a) unchanged Which are the correct IUPAC names of the following compound? The IUPAC name of the following compound is ……… What is isomerism? Step 3. KOH (d) Statement – I is wrong but statement – II is correct. Double bond equivalent formula = ( C – \(\frac {1}{2}\) + \(\frac {1}{2}\)) How is propyne prepared from an alkyene dihalide? Samacheer Kalvi 10th Model Question Papers. Answer: Question 12. Ethane, Question 22. Suggest a route to prepare ethyl hydrogen sulphate (CH, Match the reagent from Column I which on reaction with CH. Answer: Answer: When an aqueous solution of potassium succinate is electrolysed between two platinum electrodes, ethene is produced at the anode. The parent hydrocarbon is pentane. Kolbe’s electrolytic method is suitable for the preparation of symmetrical alkanes, that is alkanes containing even number of carbon atoms. Give the IUPAC name of the following compounds. CH3MgX + HOH → CH4 – Mg(OH)X. CH3 – CH = CHCl. Answer: Question 13. Answer: Answer: Question 5. Samacheer Kalvi 11th Chemistry Hydrocarbons Multiple Choice Questions. Propyne (A) reacts with mercuric sulphate and dil. Answer: Question 44. Question 3. A compound is said to be aromatic, if it obeys the following rules: This is known as Huckel’s rule. (a) Propene + O3 : HCHO + CH3 CH0 (b) Ethane Answer: Acetylene can be manufactured in large scale by action of calcium carbide with water. An ethyl group is attached to carbon atom 3 and two methyl groups are attached to carbon atoms 2 and 3. Answer: This reaction is known as the Wurtz reaction. Propyne (A) on passing through red hot iron tube at 873 K will give mesitylene (C). Question 2. 2, 3 – Dimethyl – 6 – (2 – rnethylpropyl) decane 5 – (1,2 – Dimethylpropyl) – 2- methylnonane. Benzene undergoes Fnedel crafi’s alkylation followed by chlorination and it leads to the formation of 4-chiorotoluene. Answer: The order of reactivity of different hydrogen halides (HCl, HI , HBr) is ……….. Answer: Therefore phenolic group activates the benzene ring for electrophilic attack at oriho and para positions. Answer: A undergoes hydrogenation to give a cyclic compound (B). Answer: (a) Both (A) and (R) are correct and (R) is the correct explanation of (A). Answer: Match the following reactants in Column I with the corresponding reaction products in Column II. (iv) Ethyl – isopropyl – acetytene the major product obtained is ………, Question 6. The H-Cl bond is stronger (430.5 k.J mol-1) than H-Hr bond (363.7 kJ mol-1), thus H-Cl is not cleaved by the free radical. Statement – II : Because they are having same molecular formula but differs only in the structural formula. (a) CH3-CH3 It is found in cigarette smoke, in tobacco and and charcoal boiled food. Explain pyrolysis method. Secondary carbocation is more stable than primary carhocation and it predominates over the primary carbocation. The H-I bond is further weaker (296.8 kJ mol-3) than H-Cl bond. Little activity, Question 15. 5 – (2 – Ethylbutyl) – 3, 3 – dimethyldecane AlCl3 + CH3Cl → ⊕CH3 + AlClΘ. (a) Catalytic hydrogenation of propene (b) Statement-I and II are correct but statement-II is not correct explanation of statement-I 1. (c) Alc. The group which increases the electron density at mcta position are called as rneta directors. Answer: Question 1. Benzene undergo twice the time nitration to give m-dinitrobenzene. (c) Chloroethene Therefore to make a grignard solution, only ether is the best solvent and water or alcohol are not used for that purpose. Answer: Question 6. This effect is called as peroxide effect. C5H10 – Pentene (3 isomers) Explain why -OH group is an ortho-para director and activator. Inspired designs on t-shirts, posters, stickers, home decor, and more by independent artists and designers from around the world. When phenol reacts with Zn-dust under dry distillation conditions it gives ……….. C6H12 – Hexene (5 isomers) A is benzene (C6H6), a simple aromatic hydrocarbon, 2. Huckel proposed that aromaticity is a function of electronic structure of an organic compound. (c) H2C = C = O, Question 11. Acetylene undergoes two types of polymerisation reactions, they are: 1. n – hexane passed over chromic oxide supported on alumina at 873 K will give ………. Cyclohexane, Question 40. (a) Statement – I and II are correct and statement – II is correct explanation of statement – I, Question 10. Answer: Answer: Ozonolysis and nolvmerisation are some of the characteristic reaction of alkenes. Question 36. Answer: (a) Eclipsed (c) Cumene The above process can be catalysed by nickel at 298 K. This reaction is known as Sabalier-Sendersens reaction. Your email address will not be published. Which one of the following is not an ortho-para director? (d) CnH2n+2 (c) 1 ,2 – dichioro – 2 – methylpropane (ii). Answer: Hence, there are three ways is which benzene can be represented. Explain. Ethan started the group and Hila joined with him. An alkyl halide with molecular formula C6H13Br on dehydrohalogenation gave two isomeric alkenes X and Y with molecular formula C6H12. Answer: An organic compund (A) C2H4 decolourises bromine water. Consider: (a) Both (A) and (R) are correct and (R) is the correct explanation of (A). Propene reacts with HBr in the presence of peroxide to form ………… (b) Statement – I and II are correct but statement-II is not correct explanation of statement – I 1. There are two types of isomerism. Q:-Calculate the amount of carbon dioxide that could be produced when (i) 1 mole of carbon is burnt in air. (b) Conc. Staggered > Skew> Eclipsed Explain. Therefore, maximum electron density will be there in toluene, followed by benzene and it is least in pn-dinitrobenzene. Here we have provided NCERT Exemplar Problems Solutions along with NCERT Exemplar Problems Class 11. (c) Benzene Question 38. (a) Chiorobenzene It has six delocalised ir electrons. 2. On monobromination this alkane yields a single isomer of a tertiary bromide. (c) Statement-I ¡s correct but statement-II is wrong. Academia.edu is a platform for academics to share research papers. Question 9. (c) Ethene 2. Step 1: Question 6. Phenol is the resonance hybrid of the following structures: When two different types of alkyl halides are taken then we get a mixture of products. (a) Nitrobenzene, Question 24. (1). Answer: Mention the types of isomerism? (b) PS : disposable utensils (c) Ethene When a solution of haloalkanc in dry ether is treated with sodium metal, higher alkanes are produced. (2) Benzene reacts with bromine in the presence of iron to give substituted C6H5Br. Answer: Answer: vander Waal’s repulsion and steric hindrance make the molecule much more unstable. Dienes are the name given to compounds with ………. (b) Ethene + O3 : CH3 CHO + H2O2 alkane, Question 14. This reaction is stereospecific giving only the trans-2-butene. Answer: Aqueous solution of potassium succinate is electrolysed to give …………. Calculate the number of rings present in C18H12. Propene reacts rjth cone. Question 1. Answer: (b) Staggered H2SO4 at 333 K to give B. (iii) Presence of (4n+2) π−electrons in the ring where n is an integer (n = 0, 1, 2,………..) [Huckel rule]. Explain the mechanism involved in the reaction between Tertiary alkyl halide and primary alkoxide with eample. (c) the staggered conformation of ethane is less stable than eclipsed conformation, because staggered conformation has torsional strain. All the σ-bonds in benzene lies in one plane with bond angle of 120º. [NEET] (d) Chlorobenzene Water molecules are polar and akanes are non-polar. (c) CH3 – CH = CH – CH3 + O3 : 2CH3COCH3 (d) Naphthalene (c) Statement – I is correct but statement – II is wrong. (iv) 4–(1-methylethyl)– 5 – (1-methylpropyl)-decane. -CN, -CHO, -COOH. Step 2 : (d) PET. 1 – Bromopropane, Question 27. (d) Statement – II is wrong but statement – II is correct. Answer: (a) C8H18 ∴ here four rings are there, four double bond equivalent arc used. (a) trans – 2 – chloro-3 iodo – 2 – pentane Question 4. A mixture of propane and butane is known as LPG gas which is used for domestic cooking purpose. Pyrolysis is defined as the thermal decomposition of an organic compound into smaller fragments in the absence of air through the application of heat. n-butane may be considered as a derivative of ethane as one hydrogen on each carbon atom is replaced by a methyl group. Step-2: During this process CO2 molecule is eliminated process and this process is known as decarboxylation reaction. Answer: Answrer: HNO3 + H2SO4 → \(\overset { \oplus }{ { NO }_{ 2 } } \) + H\(\overset { \oplus }{ { SO }_{ 4 } } \) + H2O. (c) Ethyne, Question 12. Preparation of 3 – chloronitro – benzene from benzene: (b) 2 – Butyne (d) (A) is wrong but (R) is correct. Geometrical isomers of 2 – Butene (A): Question 17. Statement – I : n – butane and iso – butane are isomers. Question 26. Answer: C5H10 – Pentene (3 isomers) Classify the following species as electrophiles and nucleophiles. (b) HI The lateral overlap of theirp-orbitals produces 3 it bond. Answer: H2S04 to form 2 – propyl hydrogen sulphate in accordance with Markovnikoffs rule Further hydrolysis yields 2-propanol. (b) cis – 3 – iodo – 4 – chloro – 3 – pentane The process of addition of H2 to unsaturated compounds (alkenes or alkynes) in known as hydrogenation. (d) CH = CH (a) Straws 5 (1,2 – Dimethyipropyl) – 2 – methylnonane (b) 2-butyne reacts with sodium in liquid ammonia: Benzene (A) reacts with Cl2 in presence of UV-light to give benzene hexachioride (C). 2. Edipsed conformation: (a) Propane Some groups decreases the reactivity of benzene ring and are known as de-activating groups. Answer: (d) (A) is wrong but (R) is correct. Benzene (A) reacts with H2 in the presence of Pt to give cyclohexane (B). Statements-II : Because of the delocalisation of electrons a strong t bond is formed which makes the molecule stable. (c) Alc. The correct statement regarding the comparison of staggered and eclipsed conformations of ethane is ……….. [NEET] Homolytic fission of benzoyl peroxide will give ……….. Question 45. (a) C4H10 BHC (Ben.zene hexachioride), Question 41. 1. (a) Acetylene: Question 18. Benzene reacts with hydrogen in the presence of Pt to yield ………. Ethane reacts with HBr to form ………… (a) HCl of hydrogen and halogen atoms and N = no. Answer: Conversion of Ethyne into Benzene: This process is one of the cyclic polymerisation process. In HBr, br is more electronegative than H. When bonded electron move towards Br, polarity is deve[oped and it creates electrophile H+ which attacks to the double bond to form a carbocation. Why does benzcnc undergo clectrophilic substitution reactions easily and nucleophilic substitution with difficulty? During the propagation step methyl free radical is produced, which is involved in the termination step, the two methyl free radical then combines to form ethane. Gasoline is a complex mixture of many hydrocarbons used as a fuel for internal combustion engines. (b) Statement-I and II are correct but statement-II is not correct explanation of statement-I Step 2 : Answer: For example, it does not decolorise the bromine water in CCl4. (c) 2, 3 – Dimethylbut – 1 – ene Write the mechanism for following reaction. Why benzene undergoes substitution reaction rather than addition reactions under normal conditions? Formation of electrophile: Markovnikoff’s rule: When an unsymmetrical alkene reacts with hydrogen halide, the hydrogen adds to the carbon atom that has more number of hydrogen and halogen adds to the carbon atom having fewer hydrogen atoms. Addition of hydrohalides to alkene is an example for ………… A reacts with mercuric sulphate and dil. Skew formation: (a) Formaldehyde Step 2. Why are alkanes called paraffins? molecule with three double bonds. Toluene has a methyl group on the benzene ring which is electron releasing group and hence activate the benzene ring by pushing the electrons on the benzene ring. alkaline KMNO4, Question 28. Thus, the acidic character decreases in the order The rotation about C-C single bond axis yielding several arrangements of a hydrocarbon called conformers. (a) Both (A) and (R) are correct and (R) is the correct explanation of (A). Answer: This indicates that benzene is a highly unsaturated compound. namely. aromatic, Question 37. (b) 1 – chloro – 2 – iodo – 2 – methylpropane (b) Phenol (a) (i) and (ii), Question 9. Answer: 5 – (2 – Ethylbutyl) – 3, 3- dimethyldecane 1. 4. What are combustion reactions? Question 19. Question 2. Step 4. 3. This is because, the secondary carbocation formed during the reaction is rearranged to give the more stable tertiary carbocation. Phenol is the resonace hybrid of following structure. (a) They contain (4n+2) π electrons BHC is I3enzene hexachioride. (i) C2H4 (A), decolourises the bromine water. The actual structure of the molecule is said to be a resonance hybrid of the various possible alternative structures. Which of the following will not show geometrical isomerism ? (d) 2, 2, 3, 3 – tetrachlorobutane (c) configurational isomers Benzene is a flat hexagonal molecule with all carbons and hydrogen lying in the same plane with a bond angle of 120º. Question 17. Answer: Answer: 5. Which of the above statement is/are correct’? Addition of HBr to secondary free radical. Which one of the following is not a monocyclic aromatic hydrocarbon? Why? (b) Both (A)and (R) are correct hut (R) is not the correct explanation of (A). (d) none of these It came out on May 22nd, 2020, two weeks and four days after the previous episode. (b) Toluene How will you prepare ethene from ethanol? In this conformation, the hydrogen’s of both the carbon atoms are tir apart from each other. (c) (iii) only (d) the staggered conformation of ethane is less stable than eclipsed conformation, because staggered conformation has no torsional strain. (c) – OH Assertion (A): tert-Butyl bromide undergoes Wurtz reaction to give 2, 2, 3, 3-tetramethylbutane. Answer: Answer: (b) Ethene Calculate the percentages of all monochlorinated products obtained from 2-methylbutane. Question 19. (b) 2 – Methylbut – 2 – ene Question 11. Let us consider the directive influence of aldehydic (-CHO) group. How propene is prepared form 1, 2-dichloropropane? C6H12 – Hexene (5 isomers) C6H5, Question 26. Explain the mechanism of addition of HBr to propenc. (b) CH3 – CH2 – CH2 – OH Step 2: (ii) Birch reduction is stereospecific in reaction. Draw the structural formula for 4,5 -diethyl -3,4,5-trimethyloiane (b) CH4. Same alkane can be prepared by …….. Explain with suitable example. Benzene reacts with Cl2 in the presence of sunlight to give ……….. (c) configurational isomers. No isomers of C6H5Br was identified. Answer: Question 15. Thank you :) (c) Statement – I is correct but statement – II is wrong. 3. (ii) activates the ring by inductive effect. Addition of HBr to propene yields 2-bromopropane, while in the presence of benzoyl peroxide, the same reaction yields 1-bromopropane. Answer: Write the mechanism of Freidel craft’s acylation. Question 30. 3. 1. (a) 2 – Methylpentane All orders are custom made and most ship worldwide within 24 hours. (c) C8H14 Methane present in natural gas is used in home heating. Answer: Question 23. (a) Oct – 4 – ene Alkenes are used as starting material in the synthesis of alcohols, plastics, detergents and fuels. Answer: Question 24. Answer: Given an example. Therefore the electron density at ortho and para positions increases as compared to the metci position, thus phenolic group activities the benzene ring for electrophilic attack at ortho and para positions and hetice – OH group is an ortho-para direction or and an activator. Question 35. (c) But-2-ene + O3 : HCHO + H2 O2 Question 6. Answer: Isomerisation is a chemical process by which a compound is transformed into any of its isomeric form. In which of the following molecules, all atoms are co-planar? Cyclo hexane, Question 3. (a) Both (A) and (R) are correct and (R) is the correct explanation of (A). This proves that benzene is a hexagonal Baeyer’s reagent is ………… Ethyne > Benzene > Hexane, Samacheer Kalvi 11th Chemistry Hydrocarbons 5 Mark Questions. Hence unlike alkenes and alkynes, benzene undergoes substitution reactions rather than addition reactions under normal conditions. Question 3. (c) CH3(CH2)3CH(Br)CH3 Which one of the following shows three possible isomeric structures’? Answer: Answer: This is because the octet of electrons around the sulphur atom is not reacted. When phenol vapours are passed over zinc dust then it is reduced to benzene: Question 41. Generation of CH3CO electrophile: Step 2 : Match the reactions given in Column I with the reaction types in Column II. Answer: How ozone reacts with 2-methyl propene? In the absence of air, whai alkane are vapours passed through red-hot metal it breaks into simpler hydrocarbons. Identify A, B, and C and explain the reactions.