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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
Which of the following reaction is not correct ?A. `CH_3undersetoverset(|)(Cl) overset(LiAlH_4)(to) CH_3CH_2CH_3`B. `(CH_3)_3"CC"l overset(LiAlH_4)(to) (CH_3)_3CH`C. `(CH_3)_3"CC"l overset(NaBH_4)(to) (CH_3)_3CH`D. `CH_3l+HI overset(420K)(to) CH_4+I_2` |
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Answer» Correct Answer - B `LiAlH_4 " converts " 3^@` alkyl halide into alkene `(CH_3)_3"CC"l overset(LiAlH_4)(to)(CH_3)_3CH` Thus, (b) is incorrect . |
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| 152. |
Which of the following alkanes can be easily sulphonated?A. n-butaneB. iso-butaneC. n-pentaneD. n-hexane |
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Answer» Correct Answer - D n-hexane can be easily sulphonated. |
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| 153. |
Which of the following alkanes has only primary hydrogen atoms?A. `2,2,3,3`-TetramethylbutaneB. `3,4,4,5`-TetramethylpentaneC. `2,2,4,4`-TetramethylpentaneD. `2,2,4`-Tetramethylpentane |
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Answer» Correct Answer - A `overset(1^(@))CH_(3)-underset(2,2,3,3-"Trimethylbutane")(underset(1^(@))underset(CH_(3))underset(|)overset(1^(@))overset(CH_(3))overset(|)C-underset(1^(@))underset(CH_(3))underset(|)overset(1^(@))overset(CH_(3))overset(|)C-overset(1^(@))CH_(3))` |
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| 154. |
How many dichloro products are formed in the above reaction (including stereoisomers) ?A. 5B. 6C. 7D. 9 |
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Answer» Correct Answer - C |
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| 155. |
The population of eclipsed -like conformationsA. increases with increase of temperatureB. increases with decrease of temperatureC. decreases with increase of temperatureD. remains unchanged with change of temperature |
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Answer» Correct Answer - A Because repulsive interactions are easily overcome by molecules with rising temperature. `(CH_(3))CHoverset(H_(2)SO_(4)//SO_(3))rarr(CH_(3))_(3)CSO_(3)H+H_(2)SO_(4)` |
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| 156. |
Natural gas is a mixture ofA. `CO+N_2`B. `CH_4+C_2H_6+C_3H_8`C. `CO+CO_2`D. `CO+H_2+CH_4` |
| Answer» Correct Answer - B | |
| 157. |
Which of the following statements is not true of natural gas?A. It is a mixture of `CO and H_2`B. It is a mixture of gaseous hydrocarbonsC. It is a fuelD. It is used in the manufactures of fertilizer |
| Answer» Correct Answer - D | |
| 158. |
Gasoline has compounds havingA. `C_3-C_5`B. `C_5-C_8`C. `C_8-C_10`D. `C_10-C_20` |
| Answer» Correct Answer - B | |
| 159. |
Action of HCI on `(CH_3)_2C=CH_2` and on `CH-=CH` will predominantly give the compounds repectivelyA. `(CH_3)CHCH_2CI and CH_2CI-CH_2CI`B. `(CH_3)_2"CC"ICH_3 andCH_3CHCI_2`C. `(CH_3)_2CHCH_2CI andCH_3CHCI_2`D. `(CH_3)_2CHCH_3 and CH_3CI-CH_3CI` |
| Answer» Correct Answer - B | |
| 160. |
A tertiary carbon is bonded directly toA. 2 HydrogensB. 3 CarbonsC. 2 CarbonsD. 4 Carbons |
| Answer» Correct Answer - B | |
| 161. |
In the formation of methane molecule carbon makes use ofA. unhybridised orbitalsB. sp-hybridised orbitalsC. sp2 hybridised orbitalsD. sp3 hybridised orbitals |
| Answer» Correct Answer - D | |
| 162. |
Percentage of hydrogen is maximum inA. `C_2H_2`B. `C_2H_4`C. `C_2H_6`D. `CH_4` |
| Answer» Correct Answer - D | |
| 163. |
For the alkane `C_4H_10`, which of the following is not correct structure of normal isomer?A. `CH_3-CH_2-CH_2-CH_3`B. `CH_3-CH_2-undersetunderset(CH_3)(|)CH_2`C. `oversetoverset(CH_3)(|)CH_2-CH-CH_3`D. `CH_3-undersetunderset(CH_3)(|)CH-CH_3` |
| Answer» Correct Answer - D | |
| 164. |
The highest boiling point is expected for:A. Iso-octaneB. n-OctaneC. 2,2,3,3-tetramethylbutaneD. n-Butane |
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Answer» Correct Answer - B For isomeric alkanes, branched chain isomers. |
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| 165. |
Among the following select the alkane that is expected to have lowest boiling pointA. HexaneB. 2-MethylpentaneC. 3-MethylpentaneD. 2,2-Dimethylbutane |
| Answer» Correct Answer - D | |
| 166. |
An alkane molecule isA. very weakly polarB. nonpolarC. both (1) and (2)D. highly polar |
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Answer» Correct Answer - C `C` and `H` atoms of the alkane molecule are held together entirely by covalent bonds. These bonds either join two `C` atoms and hence, are nonpolar, or join `C` and `H` atoms that differ very little in electonegativity `(2.5 "for" C and 2.1 "for" H)` and hence, are only slightly polar. Furthermore, these bonds are directed in a very symmetrical way ( tetrahedral orientation) so that the slight bonds polarities tend to cancel out. As a result, an alkane molecule is either nonopolar or very weakly polar. |
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| 167. |
How many moles of `HI` are used to reduced one mole of monohydric alcohol ?A. SixB. FourC. ThreeD. Two |
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Answer» Correct Answer - D `ROH+2HIoverset(Red P)underset(Delta)rarrRH+2H_(2)O+I_(2)` |
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| 168. |
Why do the C-C bonds rather than the C-H bonds break during pyrolysis of alkanes? |
| Answer» bond energy of C-C bond is lower than bond energy of C-H bond. | |
| 169. |
Alkanes are usually unreactive under ordinary conditions because (i) the `C-C and C-H` bonds are quite strong (ii) the `C-C` bonds are nonpolar and `C-H` bonds are weakly polar (iii) they have no unshared electrons (iv) they do not possess any functional groupA. (i), (ii)B. (iii), (iv)C. (i), (ii), (iii)D. (i), (ii), (iii), (iv) |
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Answer» Correct Answer - D This is low reactivity of alkanes toweards many reagents accounts for the fact that alkanes were originally called paraffins. |
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| 170. |
The common name of the following alkane is `CH_3-underset(underset(CH_3)|)overset(overset(CH_3)|)C-CH_3-underset(underset(H)|)overset(overset(CH_3)|)C-CH_3`A. 2,2,4 trimethyl pentaneB. OctaneC. Iso octaneD. 4,4,2 trimethyl pentane |
| Answer» Correct Answer - C | |
| 171. |
Which of the following has the maximum solubility in a given nonpolar solvent?A. `CH_(4)`B. `C_(2)H_(6)`C. `C_(3)H_(8)`D. `C_(4)H_(10)` |
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Answer» Correct Answer - A On account of the weakest intermolecular forces, methane is more soluble than any of its homologs. |
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| 172. |
How many primary and secondary carbon atoms are present in neopentane respectively?A. 4,1B. 4,0C. 0,4D. 4,4 |
| Answer» Correct Answer - B | |
| 173. |
When the neopentane is added to water, it floats becauseA. it is spherical in shapeB. it is insoluble in waterC. it is less dense than waterD. both `(2) and (3)` |
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Answer» Correct Answer - C All alkanes are less dense than water. |
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| 174. |
Cyclohexane floats on water becauseA. it is immiscible with waterB. its density is less than that of waterC. it is an non-polar substanceD. it is an immiscible and lighter than water |
| Answer» Correct Answer - D | |
| 175. |
An alkane cannot be chlorinated by using which of the following reagents?A. `Cl_(2)//hv`B. `HCl`C. `SO_(2)Cl_(2)`D. `t-Bu-O-Cl` |
| Answer» Correct Answer - B | |
| 176. |
The number of theoretically possible conformations of an alkane isA. infiniteB. twoC. FourD. Three |
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Answer» Correct Answer - A Alkanes can have infinite number of conformations by the rotation of one part of the molecule keeping the other part at rest by rotation aroung a `C-C` single bond by as small angle as possible. |
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| 177. |
The number of theoretically possible conformations of an alkane isA. TwoB. ThreeC. fourD. Infinite |
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Answer» Correct Answer - D Infinite number |
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| 178. |
Propane can be best prepared by the reaction:A. `CH_(3)CH_(2)I+CH_(3)I+Naoverset(E_(2)O)to`B. `CH_(3)CH_(2)COONa+CH_(3)COONaunderset("Electrolysis")overset(H_(2)O)to`C. `CH_(3)CH_(2)Br+(CH_(3))_(2)CuLioverset(Et_(0)O)to`D. `CH_(3)CH_(2)CH_(2)COONaunderset(CaO.Delta)overset(NaOH)to` |
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Answer» Correct Answer - C Corey house synthesis |
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| 179. |
Propane can be best prepared by the reactionA. `CH_(3)CH_(2)CH_(2)COONaunderset(CaO,Delta)overset(NaOH)rarr`B. `CH_(3)CH_(2)Br+(CH_(3))_(2)CuLioverset(Et_(2)O)rarr`C. `CH_(3)CH_(2)I+CH_(3)Iunderset(Et_(2)O)overset(Na)rarr`D. `CH_(3)CH_(2)COONa+CH_(3)COONaunderset("Electrolysis")overset(H_(2)O)rarr` |
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Answer» Correct Answer - B In all other cases, We get a mixture of products. |
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| 180. |
Hydbridization of `C` atom in methylsodium isA. `sp^(3)d`B. `sp`C. `sp^(3)`D. `sp^(2)` |
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Answer» Correct Answer - C `CH_(3)^(-)Na^(+)`, methylsodium. The hybridization of `C` of carbanion is `sp^(3)`. |
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| 181. |
The pair of structures given below representsA. EnantiomersB. DiastereomersC. Structural isomersD. Two molecules of the same compound |
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Answer» Correct Answer - C They are structural isomers |
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| 182. |
Methane can be prepared byA. the reaction of iodomethane with sodium in dry etherB. ther reaction of methanol with concentrated `H_2SO_4`C. the reaction of sodium methanoate with soda-limeD. the reaction of sodium ethanoate with soda-lime |
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Answer» Correct Answer - D `CH_3COONa+NaOHunderset(Delta)overset(CaO)toCH_4+Na_2CO_3` |
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| 183. |
It is necessary to use__________ in the iodination of alkane.A. AlcoholB. Oxidising agentC. BenzeneD. Reducing agent |
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Answer» Correct Answer - B Oxidising agent removes HI formed. HI makes the reaction reversible. |
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| 184. |
The number of carbons atoms in hydrocarbon of kerosene oil is in the range ofA. `C_5-C_7`B. `C_10-C_16`C. `C_1-C_4`D. `C_17-C_20` |
| Answer» Correct Answer - B | |
| 185. |
Saturated hydrocarbons undergoA. substitution reactionsB. addiction reactionsC. polymerization reactionsD. condensation reactions |
| Answer» Correct Answer - A | |
| 186. |
Preparation of oil gas or petrol gas from kerosene oil or petrol involves the principle ofA. IsomerisationB. ArommatisationC. PyrolysisD. all the above |
| Answer» Correct Answer - C | |
| 187. |
Conversion of high molecular weight hydrocarbons into low molecular weight hydrocarbons in te absence of air is known asA. PolymerisationB. HydrolysisC. PyrolysisD. Isomerisation |
| Answer» Correct Answer - C | |
| 188. |
Sodium salt of which acid will be needed to prepare propane by decarboxylation?A. Propanoic acidB. Butanoic acidC. Ethanoic acidD. A mixture of methanoic and ethanoic acid |
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Answer» Correct Answer - B `RCOONaoverset(NaOH)underset(CaO)rarrRH` Both salt and alkane contain the same alkyl group. `underset("Sodium buta noate")(CH_(3)CH_(2)CH_(2))-COONararrunderset("Propane")(CH_(3)CH_(2)CH_(2))-H` |
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| 189. |
The compound with the highest boiling point is:A. n-PentaneB. 2-MethylbutaneC. n-HexaneD. 2,2-Dimethylpropane |
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Answer» Correct Answer - C n-Hexane is alkane with even number of carbon atoms and high molecular weight. |
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| 190. |
The conversion `RCORrarrRCH_(2)R` cannot be effected byA. conc. `HI` and red `P at 150^(@)C`B. Wurtz reactionC. Wolff-Kishner reductionD. Clemmensen reduction |
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Answer» Correct Answer - B Conversion involves reduction which is not possible by the Wurtz reaction. |
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| 191. |
Which of the following is readily sulphonated ?A. ButaneB. IsobutaneC. NeopentaneD. Methane |
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Answer» Correct Answer - B Because it contains a `3^(@)H` atom |
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| 192. |
`Br^(**)` will abstract which of the hydrogen most readily?A. `a`B. `b`C. `c`D. `d` |
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Answer» Correct Answer - A |
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| 193. |
Radio `(overset(82)(Br)-overset(82)(Br))` adds to 1-bromocyclohexene. The product isA. is 1,1,2-tribromocyclohexaneB. has radio active bromine at vicinal positionC. has radioactive bromine at vicinal positionD. has radioactive bromine trans to each other |
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Answer» Correct Answer - A::B::C |
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| 194. |
Arrange in increasing order of heat of hydrogenation of following dienes.A. iiiltvltiltivltiiB. VltiltivltiiltiiiC. iiigtvgtigtivgtiiD. iiigtvgtivgtigtii |
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Answer» Correct Answer - A |
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| 195. |
A gas believed to be the cause of explosin in coal mine isA. `CH_4`B. `C_(2)H_6`C. `C_(3)H_(8)`D. `C_(4)H_(10)` |
| Answer» Correct Answer - A | |
| 196. |
Paraffin wax is a/ an _______.A. EsterB. AlcoholC. Unsaturated hydrocarbonsD. Saturated hydrocarbons |
| Answer» Correct Answer - D | |
| 197. |
`Xunderset((1)/(2)H_(2))overset(Na)toYunderset(Delta)overset(NaOH+CaO)toZ`, if Z is the first homologue of alkane series, then XA. Methanoic acidB. Bromo ethaneC. Ethyl alcoholD. Ethanoic acid |
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Answer» Correct Answer - D `CH_(3)COOH+NatoCH_(3)COONaunderset(CaO //Delta)overset(NaOH)toCH_(4)+Na_(2)CO_(3)` |
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| 198. |
`CH_(3)CH_(2)CH_(2)CH_(3)overset("Catalyst")rarrCH_(3)underset(CH_(3))underset(|)(C )HCH_(3)` The catalyst used in the above conversion isA. `ZnCl_(2)//HCl`B. `AlCl_(3)//HCl`C. `PdCl_(2)//HCl`D. `CuCl//HCl` |
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Answer» Correct Answer - B When `n`-alkanes are heated with anhydrous `AlCl_(3)` and `HCl at 573 K` under a pressure of about `35 atm`, they are converted into branched chain alkanes. |
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| 199. |
2,3-Dimethyl-2-butene undergoes catalytic hydrogenation to giveA. 2,3-DimethylbutaneB. 2-MethylpentaneC. 2,2-DimethylbutaneD. 3-Methylpentane |
| Answer» Correct Answer - A | |
| 200. |
`(CH_(3))_(3)-C-MgCl` on reaction with `D_(2)O` producesA. `(CH_(3))_(3)CD`B. `(CH_(3))_(3)COD`C. `(CH_(3))_(3)CH`D. `(CD_(3))_(3)COD` |
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Answer» Correct Answer - A Grignard reagent on decomposition with water or other compounds having active hydrogen give alkane. |
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