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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.
| 351. |
Which of the following statements is false about an electrophile ?A. Electron-deficient speciesB. An acidic reagentC. A reagent which attacks an electron-deficient site in a moleculeD. A species which seeks a pair of electrons. |
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Answer» Correct Answer - C Refer Comprehensive Review. |
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| 352. |
Which of the following is a false statement?A. Free radicals, carbonium ions or carbanions are reaction intermediates.B. Reaction between methane and chlorine in presence of sunlight proceeds via free radicalC. The electronegative atom in the carbon chain produces +I effectD. Homolytic fission of C-C bonds gives free radicals |
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Answer» Correct Answer - C Thee electronegative atom in the carbon chain produces -I effect. |
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| 353. |
How many of the given species will evolve `CO_(2)` with `NqaHCO_(3)`? |
| Answer» Correct Answer - 3 | |
| 354. |
The reaction `(CH_(3))_(3)Cbroverset(H_(2)O)rarr(CH_(3))_(3)C-OH` isA. elimination reactionB. substitution reactionC. free radical reactionD. displacement reaction |
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Answer» Correct Answer - B See Comprehensive Review. |
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| 355. |
Which of the following is most stable ?A. `Ph_(3)C^(+)`B. `Ph_(2)CH^(+)`C. `PhCH_(2)^(+)`D. Troplium cation. |
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Answer» Correct Answer - A Out of the given four choices, `Ph_(3)C^(+)` is most stable as the + ve charge is stabilized by three Ph rings. |
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| 356. |
Acetaldehyde is the rearragement product ofA. Methyl alcoholB. Allyl alcoholC. Vinyl alcoholD. All are correct. |
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Answer» Correct Answer - C `underset("Vinyl alcohol")(HO-CH=CH_(2)) underset("rearrangement")overset("Tautomeric")rarr underset("Acetyldehyde")(O=CH-CH_(3))` |
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| 357. |
Identify the compound that exhibits tautomerismA. lactic acidB. 2-pentanoneC. phenolD. 2-butene |
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Answer» Correct Answer - B Pentanone, `overset(alpha)(C)H_(3)Co overset(alpha)(C)H_(2)CH_(2)CH_(3)` contains `alpha`-hydrogens on a saturated carbon and hence shows tautomerism. |
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| 358. |
The ammonia evolved from the treatment of 0.03 g of an organic compound for the estimation of nitrogen was passed in 100 mL of 0.1 M sulphuric acid. The axcess of the acid required 20 mL of 0,5 M solution hydroxide solution for complete neutralisation. the organic compound is :A. acetamideB. benzamideC. ureaD. thiourea. |
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Answer» Correct Answer - C Volume of unused `H_(2)SO_(4)` `{:(N_(1)V_(1),equiv,N_(2)V_(2)),("(acid)",,"(base)"):}` `0.2xxV_(1)=0.5xx20` `V_(1)=(0.5xx2.0)/(0.2)=50 mL` (b) Volume of `H_(2)SO_(4)` used `=100-50=50 mL` `%` of nitrogen in the compound `=(1.4xxVxxN)/(W)` `=(1.4xx50xx0.2)/(6.30)=46.60 %` The percentage of nitrogen is the same as in urea `(NH_(2)CONH_(2))` `=("Mass of N")/("Mass of Urea")xx100` `=28/60xx10=46.6 %` |
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| 359. |
`: C Cl_(2)` isA. an electrophileB. a free radicalC. a nucleophileD. none of these |
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Answer» Correct Answer - A Nucleophiles are electron rich species and hence they are Lewis bases. |
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| 360. |
Which of the following is the most correct electron displacement for a nucleophilic reaction to take place ?A. B. C. D. |
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Answer» Correct Answer - A In nucleophiles displacement reaction, the flow of electrons occurs in a manner which expels the weaker nucleophile, i.e., `Cl^(-)` ion. Thus, option (a) is correct. |
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| 361. |
Which of the following does not exhibit tautomerism ?A. B. C. D. |
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Answer» Correct Answer - A For tautomerism to occur, at least one `alpha`-hydrogen should be presented on a saturated carbon next to the keto group. Since in option (a), `alpha`-hydrogens are not present on a saturated carbon and hence it does not show tautomerism. While all, other options contain `alpha`-hydrogens on saturated carbons next to the keto group and hence show tautomerism. |
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| 362. |
Consider the following compound: The `IUPAC` name of the this compound isA. 5,6-diethyl-3-methyldecaneB. 5,6-diethyl-3-methyldec-4-eneC. 3,5,6-triethyldec-6-eneD. 3,5,6-trimethyldec-6-ene |
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Answer» Correct Answer - B `C_(6)H_(5)-Cl,CH_(2)=CHCl,C_(6)H_(5)Br" and "CH_(3)COO^(-)` are all stabilized by resonance |
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| 363. |
Which one of the following compounds cannot show tautomerism ?A. `CH_(3)-underset(O)underset(||)(C )-CH_(3)`B. `CH_(2)=CH-OH`C. D. |
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Answer» Correct Answer - D The compound listed under option (d) does not contain an `alpha`-hydrogen on a saturated carbon next to the keto group and hence cannot show tautomerism. |
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| 364. |
Which of the following carbocation is most stable?A. `Ph_(3)C^(+)`B. `(CH_(3))_(2)C^(+)H`C. `CH_(3)CH_(2)^(+)`D. `CH_(2)=CH-CH_(2)^(oplus)` |
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Answer» Correct Answer - A See carbocation. |
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| 365. |
Which one of the following compounds cannot show tautomerism?A. `CH_(3)-underset(O)underset(||)C-CH_(3)`B. `CH_(2)=CH-OH`C. D. |
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Answer» Correct Answer - D The compound listed in (d) has no `alpha` hydrogen on a saturated carbon next to the keto group and hence cannot show tautomerism. |
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| 366. |
Which of the following statements regarding the resonance energy of benzene is correct?A. The energy required to break the C-H bond in benzeneB. The energy required to break C-C bond in benzeneC. The energy is a measure of stability of benzeneD. The energy required to convert. |
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Answer» Correct Answer - C Resonance energy is a measure of stability. |
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| 367. |
The rate of the reaction is influenced by the hyperconjugation effect of group R. If R is sequentially `CH_(3)^(-)` (II) `CH_(3)-CH_(2)` (III) `CH_(3)-underset(CH_(3))underset(|)CH-` , (IV) `H_(3)C-overset(CH_(3))overset(|)underset(CH_(3))underset(|)C-` the increasing order of speed of above reaction isA. IV,III,II,IB. I,II,III,IVC. I,IV,III,IID. III,II,I,IV |
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Answer» Correct Answer - B More the number of H atoms on the `alpha` carbon of the group R, more are the hyper conjugation structures, weaker is the C-B bond and hence higher is the rate of reaction. Now since `CH_(3)` has three, ethyl has two, iso- propyl has one and tert butyl group has no `alpha`-hydrogen, therefore, hyper conjugation effect decreases and hence the rate decreases in the same order (B), is correct |
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| 368. |
Hperconjugation effect is also calledA. Baker-Nathan effectB. Anchimeric assistanceC. No bond resonanceD. All are correct. |
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Answer» Correct Answer - D Hyperconjugation is also called Baker-Nathan effect, no bond resonance, anchimeric assistance. |
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| 369. |
Which of the following statements regarding resonance is `NOT` correct?A. the different resoanating structures of a molecule have fixed arrangement of atomic nucleiB. the different resonance structures of a molecule should have same number of unpaired electronsC. the hybrid structure has equal contribution from all the resonating structureD. None of the individual resonating structures explains the various characteristics of the molecule. |
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Answer» Correct Answer - C (i) Resonating structure have fixed arrangement of atomic nuclei (II) None of the individual resonating structure explains the various characteristics of the molecule (iii) Different resonating structures should have same number of unpaired electrons. |
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| 370. |
Which of the following group has the maximum hyperconjugation effect ?A. `CH_(3)-`B. `CH_(3)CH_(2)-`C. `(CH_(3))_(2)CH-`D. `(CH_(3))_(3)C-` |
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Answer» Correct Answer - A `CH_(3)-`with three H-atoms has maximum hyperconjugation effect. |
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| 371. |
Which of the following carbocations is most stable ?A. B. C. D. |
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Answer» Correct Answer - A `(CH_(3))_(3)overset(+)C` is the most stable on account of highest hyperconj ugation effect and less steri c hinderance. |
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| 372. |
Which of the following carbocations will be the most stable?A. `Ph_(3)C^(+)`B. `CH_(3)Coverset(+)H_(2)`C. `(CH_(3))_(2)Coverset(+)H`D. `CH_(2)=CH-Coverset(+)H_(2)` |
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Answer» Correct Answer - A Stability order of cabocations `PhC^(+)gt(CH_(3))_(2)C"C"H^(+)gtCH_(3)overset(+)CH_(2)gtCH=CH-overset(+)CH_(2)` |
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| 373. |
Which of the following carbocations is least stable ?A. `C_(6)H_(5)overset(+)CH_(2)`B. `p-NO_(2)-C_(6)H_(4)-CH_(2)^(+)`C. `p-CH_(3)O-C_(6)H_(4)-CH_(2)^(+)`D. `p-Cl-C_(6)H_(4)-CH_(2)^(+)` |
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Answer» Correct Answer - B `p -NO_(2)-C_(6)H_(4) - overset(+)CH_(2)` is the least stable carbocation. This is due to the electron withdrawing effect of - `NO_(2)` group at p-position |
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| 374. |
Which fo the following carbocations is least stable ?A. `CH_(3)overset(+)CH_(2)`B. `CH_(2)=overset(+)CH`C. `CHequivC^(+)`D. `C_(6)H_(5)^(+).` |
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Answer» Correct Answer - A `CH_(3)overset(+)CH_(2)` is the most stable carbocation. This can be explained as follows. The electronegativity of carbon increases as its hybridisation from `sp^(3)`. to `sp^(2)` to sp i.e., carbon which is `sp^(3)`-hybridised is least electronegative and `sp^(2)`-hybridised carbon is most electronegative. An element with least electronegativity can best accommodate + ve charge. In `CH_(3)overset(+)CH_(2)`, carbon is `sp^(3)` hybridised |
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| 375. |
Which of the following carbocations is the least stable ?A. B. `CH_(2)=CH^(+)`C. `CH_(2)=CH-overset(+)CH_(2)`D. `CH_(3)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)(C^(+))` |
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Answer» Correct Answer - B Carbocations A and C can show resonance. Carbocation D is stable due to + I effect of the three methyl groups. |
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| 376. |
Rank the given species in the increasing order of water solubility |
| Answer» `underset("Increasing solubility in water")overset(IIltIltIIIltIV)rarr` | |
| 377. |
Explain why the following two structures `(I)` and `(II)` cannot be the major contributors to the real structures of `CH_3COOCH_3`. . |
| Answer» The two structures are less important contributors as they involve charge separation. Additionally, structure I contains a carbon atom with an incomplete octet. | |
| 378. |
Explain why `(CH_(3))_(3)overset(+)C`is more stable than `CH_(3)overset(+)CH_(2)` and `CH_(3)` is the least stable cation |
| Answer» Hyperconjugation interaction in `(CH_(3))_(3)overset(+)C` is greater than in `CH_(3)overset(+)CH_(2)` as the `(CH_(3))_(3)overset(+)C` has nine C-h bonds. In `CH_(3)`, vacant p orbital is perpendicular to the plane in which C-H bonds lie, hence cannot overlap with it. Thus, `overset(+)CH_(3)` lacks hyperconjugative stability | |
| 379. |
Explain why `(CH_(3))_(3)overset(+)(C)` is more stable than `CH_(3)overset(+)(C)H_(2)` and `overset(+)(C)H_(3)` is the least stable cation. |
| Answer» `(CH_(3))_(3)overset(+)(C)` has nine `alpha`-hydrogens and hence has nine hyperconjugation structures while `CH_(3)overset(+)(C)H_(2)` has only three `alpha`-hydrogens and hence has only three hyperconjugation structures. As a result, `(CH_(3))_(3)C^(+)` is more stable than `CH_(3)CH_(2)^(+)`. In contrast in `CH_(3)^(+)`, the vacant p-orbital is perpendicular to the plane in which the three C-H bonds lie and hence cannot overlap with it. Thus, `CH_(3)^(+)` is not stabilized by hyperconjugation and hence is the least stable of the three cations. | |
| 380. |
Direction (Q. Nos. 19-20) Consider the following four compounds (I) `CH_(3) - CH_(2) - CH_(2) - CH_(2) - overset(O)overset(||)(C) - H` (II) `CH_(3) - CH_(2) - CH_(2) - overset(O)overset(||)(C) - CH_(3)` (III) `CH_(3) - CH_(2) - underset(O)underset(||)(C) - CH_(2) - CH_(3)` (IV) `CH_(3) - underset(CH_(3))underset(|)(CH) - CH_(2) - underset(O)underset(||)(C) - H` Which of the following pairs are not functional group isomers ?A. II and IIIB. II and IVC. I and IVD. I and II |
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Answer» Correct Answer - A::C Two or more compounds having the same molecular formula but different functional groups are called functional isomers. I. Aldehyde II. Ketone III. Ketone IV. Aldehyde Here, II and III, I and IV are not functional group isomers. Thus, options (a) and (c) are correct |
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| 381. |
Explain, how is the electronegativity of carbon atoms related to the state of hybridisation in an organic compound ? |
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Answer» Electrongeativity of carbonn atom, also depends on the hybidisation of the carbon atom. Since, s-electrons are more strongly attracted by the nucleus than p-electons, thus, electronegativity increases with increase in s-character of the hybridised orbital i.e., `underset(sp^(3) lt sp^(2) lt sp)overset(25% 33.3% 50%)rarr` Hybridisation `underset(underset("of electronegativity")("Increasing order"))overset(overset("Increasing order")("of % s-character"))rarr` Thus, sp-hybridised carbon is the most electronegative carbon |
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| 382. |
Direction (Q. Nos. 19-20) Consider the following four compounds (I) `CH_(3) - CH_(2) - CH_(2) - CH_(2) - overset(O)overset(||)(C) - H` (II) `CH_(3) - CH_(2) - CH_(2) - overset(O)overset(||)(C) - CH_(3)` (III) `CH_(3) - CH_(2) - underset(O)underset(||)(C) - CH_(2) - CH_(3)` (IV) `CH_(3) - underset(CH_(3))underset(|)(CH) - CH_(2) - underset(O)underset(||)(C) - H` Which of the following pairs are position isomers ?A. I and IIB. II and IIIC. II and IVD. III and IV |
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Answer» Correct Answer - B When two or more compounds differ in the position of substituent atom or functional group on the carbon skeleton, they are called position isomers `CH_(3) - CH_(2) - CH_(2) - overset(O)overset(||)(C) - CH_(3)` (II) `CH_(3) - CH_(2) - underset(O)underset(||)(C) - CH_(2) - CH_(3)` (III) Here, position of `-underset(O)underset(||)(C) - ` vaires. Thus, II and III are position isomers |
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| 383. |
I. `CH_(3) - CH_(2) - CH_(2) - CH_(2) - OH` II. `CH_(3) - CH_(2) - underset(OH)underset(|)(CH) - CH_(3)` III. `CH_(3) - underset(OH) underset(|)overset(CH_(3))overset(|)(C) - CH_(3)` IV. `CH_(3) - underset(CH_(3))underset(|)(CH) - CH_(2) - OH` V. `CH_(3) - CH_(2) - O - CH_(2) - CH_(3)` VI. `CH_(3) - O - CH_(2) - CH_(2) - CH_(3)` VII. `CH_(3) - O - underset(CH_(3))underset(|)(CH) - CH_(3)` Which of the above compounds form pairs of metamers ? |
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Answer» Metamerism arises due to different alkyl chains on either side of the functional group in the molecule. In the given structure V and VI or VI and VII form a pair of metamers because they differ in carbon atoms on the either side of the functional group, i.e., O-atom. `{:(V. CH_(3) - CH_(2) - O - CH_(2) - CH_(3)" ethoxy ethane"),(VI. CH_(3) - O - CH_(2) - CH_(2) - CH_(3) " methoxy propane"):} } "Metamers"` `{:(VI. CH_(3) - O - CH_(2) - CH_(2) - CH_(3) " methoxy propane"),(VII. CH_(3) - O - underset(underset(CH_(3))(|))(CH) - CH_(3) " methoxy isopropane" ):} } "Metamers"` |
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| 384. |
I. `CH_(3) - CH_(2) - CH_(2) - CH_(2) - OH` II. `CH_(3) - CH_(2) - underset(OH)underset(|)(CH) - CH_(3)` III. `CH_(3) - underset(OH) underset(|)overset(CH_(3))overset(|)(C) - CH_(3)` IV. `CH_(3) - underset(CH_(3))underset(|)(CH) - CH_(2) - OH` V. `CH_(3) - CH_(2) - O - CH_(2) - CH_(3)` VI. `CH_(3) - O - CH_(2) - CH_(2) - CH_(3)` VII. `CH_(3) - O - underset(CH_(3))underset(|)(CH) - CH_(3)` Identify the pairs of compounds which are functional group isomers |
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Answer» Two or more compounds having the same molecular formula but different functional groups are called function isomers. In the given structure, I, II, III, IV represent alcohols as functional group. Whereas V, VI, VII are ethers. Hence, I and V, I and VI, I and VII, II and VI, II and VI, II adn VII, III and V, III and VI, III and VII, IV and V, IV and VI, IV and VII all are functional group isomers. |
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| 385. |
What is the hybridisation of each carbon in `H_(2)C = C = CH_(2)` ? |
| Answer» The central carbon is sp-hybridized while both the terminal carbon atoms are `sp^(2)`-hybridized. | |
| 386. |
1 mole of ethyne on complete combustion givesA. 2 moles of carbon monoxide half -mole of waterB. 4 moles of carbon dioxide and 1 mole of waterC. 2 moles of carbon dioxide and 1 mole of waterD. 2 moles of carbon dioxide and 2 moles water |
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Answer» `C_2H_5+2CO_2rarr2CO_2+H_2O` When one mole of ethyne is subjected to complete combustion, 2 moles of `CO_2` and 1 mole of waterare formed |
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| 387. |
The radical is aromatic because it hasA. 6 p-orbitals and 7 unpaired electronsB. 6 p-orbitals and 6 unpaired electronsC. 7 p-orbitals and 6 unpaired electronsD. 7 p-orbitals and 7 unpaired electrons. |
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Answer» Correct Answer - B In `Ph-overset(ast)CH_(2)` free radical, C-atom of `-CH_(2)` is also `sp^(2)`-hybridised. As such the unpaired electron is present in unhybridised p-orbital which is perpendicular to the plane of the benzene ring. Thus benzyl free radical `(C_(6)H_(5)-overset(cdot)CH_(2))` has seven p-orbitals with one unpaired electron each. In is aromatic because it contains 6 `pi`-electrons is a planar ring system. |
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| 388. |
Molecular formula of a hydrocarbon is `C_5H_(10)`.What type of isomerisms are exhibited by it ? Give the structural formula of the isomes . |
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Answer» Molecular formula `C_5H_(10)` corresponds to pentene.It can exhibit position isomerism and chain isomerium . Possible structural formula are (i) `underset("1-Penten ")(CH_2=CH)-CH_2-CH_2-CH_3` (ii) `underset("2-Pentene")(CH_3-CH)=CH-CH_2-CH_3` (iii) `H_2C=overset(CH_3)overset(|)C-CH_2-CH_3` (iv) `H_2C=overset(CH_3)overset(|)C-CH_2-CH_3` `H_3-overset(CH_3)overset(|)C=CH-CH_3` (I),(ii),(iii),(iv),(v),are position isomers (i),(v),(i),(v),(iii),(ii),(iv),(ii),(v) are chain isomers |
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| 389. |
The IUPAC name for a given compound is `Cl-CH_(2)-underset(CH_(3))underset(|)C=CH-CH_(2)OH`A. 1-Chloro-2-methylbut-3-en-4-01B. 1-Chloro-2-methylbut-3-en-4-01C. 4-Chloro-2-methylbut-2-en-1-01D. 3-Chloroethylbut-2-en-1-01 |
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Answer» Correct Answer - C `underset("3-Methylbut-2-en-1-01")underset()(Cl-overset(4)CH_(2)-overset(3)underset(CH_(3))underset(|)C=overset(2)CH-overset(1)CH_(2)OH)` |
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| 390. |
IUPAC name of a hydrocarbon is given as 3,5-Dixenthyl-2-hexene.Identify the correct sequence of steps to draw its structural formula . ( 1) numbering of carbon chain( 2) locating the position of double bond ( 3) writing long chain corresponding to hexne (4) locating the methyl groups (prefixes ) at the respective positions( 5) placing hydrogens to stasisfy tetravelency of carbonA. 13254B. 32145C. 13245D. 31245 |
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Answer» (i) locating the long chains chrresponding t0 hexane (ii) numbering of carbon chain (iii) locating the position of double bond (iv) locating the methyl groups (prefixes) at the respective position (V) locating hydrogen molecules to satisfy tetrava-lency of carbon |
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| 391. |
The shape of carbanion isA. LinearB. PlanarC. PyramidalD. None of these |
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Answer» Correct Answer - C The shape of carbanion is pyramidal. |
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| 392. |
Suggest methods for the separation of the following mixtures. (i) A mixture of liquid A (b.p. 365 K) and liquid B (b.p. 356 K). (ii) A mixture of liquid C (b.p. 353 K) and liquid D (b.p. 413 K). |
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Answer» (i) Fractional distillation because the boiling points of the two liquids differ by just `9^(@)`. (ii) Simple distillation since the boiling points of the two liquids are widely apart. |
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| 393. |
The `R_(f)` values of A and B in a mixture determined by TLC in a solvent mixture are 0.65 and 0.42 respectively. If the mixture is separated by column chromatography using the same solvent mixture as a mobile phase, which of the two components, A or B, will elute first? Explain. |
| Answer» Since the `R_(f)` value of A is 0.65, therefore, it is less strongly adsorbed as compared to component B with `R_(f)` value of 0.42. Therefore, on extraction of the column, A will elute first. | |
| 394. |
An organic reaction occurs through making and breaking of bonds. The breaking of bonds may occur either homolytically leading to the formation of radicals or heterolytically generating positively and negatively charged species. The neutral species (free radicals, carbenes, nitrenes, etc.) and positively charged species being electron deifcient are collectively called electrophiles while neutral and negatively charged species which are electron rich are called nucleophiles. An organic reaction usually involves the attack of a reagent (radicals, positively and negatively charged species) on the substrate molecule). The substrate molecule, although as a whole electrically neutral, has centres of low and high electron density due to displacement of bonding electrons. These electrons displacements occur through inductive, electromeric occur through inductive, electromeric, resonance and hyperconjugation effects. Whereas inductive effects involve displacement transfer of n-and `pi`-electrons along a conjugated system. Hypercongation effects, on the other hand, involve `sigma-pi`-conjugation. Both inductive and hyperconjugation effects can be used to explain the stability of carbocations and free radicals which follow the stability order: `3^(@) gt 2^(@) gt 1^(@)`. The stability of carbanions, however, follows opposite order. The stability of a molecule can be judged on the basis of contribution of its resonance structures. Resonance structures have same position of nuclei and have same number of unpaired electrons. Among resonance structures, the one which has greater number of covalent bonds, has less separation of opposite Charges, a negative charge on more electronegative and a positive charge on a more electropostive atom are more stable than others. Which of the following is the most stable cation ?A. `F_(3)C - CH_(2)^(+)`B. `(CH_(3))_(2)CH^(+)`C. `CH_(3)^(+)`D. `CF_(3)^(-)` |
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Answer» Correct Answer - B Carbocation are stabilized by +I -effect of `CH_(3)` groups and destabilized by +I-effect of F atoms. Therefore, `(CH_(3))_(2)overset(+)(C)H` is the most stable carbocation. |
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| 395. |
Assertion : Compounds with difference in their boiling points by about `30^(@)C` can be separated by simple distillation. Reason : All liquid mixtures can be separated by distillation method.A. If both assertion and reason are correct and reason is correct explanation for assertion.B. If both assertion and reason are correct but reason is not correct explanation for assertion.C. If assertion is correct but reason is incorrect.D. If both assertion and reason are incorrect. |
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Answer» Correct Answer - C Correct reason. Only those liquid mixtures can be separated by distillation method in which at least one constituent is of volatile nature. |
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| 396. |
Which of the following species contain six electrons around the central carbon atom ?A. CarbanionB. CarbocationC. CarbeneD. Free radical. |
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Answer» Correct Answer - B::C A carbocation and a carbene has six electrons around central carbon atom `underset("A carbene")underset():underset(H)underset(|)C-H" "or .overset(cdot)underset(H)underset(|)C-H" "H-overset(+)underset(H)underset(|)C-H` |
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| 397. |
Which of the following correctely lists the configurations of cyclohexane in order increasing potential energies?A. Chair `gt` Twist boat `gt` Boat `gt` Half-chairB. Half-chair` gt`Boat `gt` Twist boat `lt` ChairC. Chair `lt` Twist boat `lt` Half-chair `lt` BoatD. Chair `lt`Boat `lt` Twist boat `lt` Half-chair |
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Answer» Correct Answer - A Among the important confermers of cyclohexane, the order of stability is half-chair `lt` boat`lt`twist boat`lt` chair. The order of potential energy is reverse of order of stability. |
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| 398. |
Which is the most stable resonating structure?A. B. C. D. |
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Answer» Correct Answer - B Negative charge on more electronegative atom is more stable. |
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| 399. |
Names of some compounds are given. Which one is not in IUPAC system ?A. `{:(" "CH_(3)),(" |"),(CH_(3)-CH_(2)-CH_(2)-CH-CH-CH_(2)CH_(3)),(" |"),(" "CH_(2)CH_(3)),(" 3-Methyl-4-ethylheptane"):}`B. `{:(CH_(3)-CH-CH-CH_(3)),(" |"" |"),(" "OH" "CH_(3)),("3-Methyl-2-butanol"):}`C. `{:(CH_(3)-CH_(2)-CH-CH-CH_(3)),(" ||"" |"),(" "CH_(2)" "CH_(3)),(" 2-Ethyl-3-methylbut-1-ene"):}`D. `underset("4-Methyl-2-pentyne")(CH_(3)-C-=C-CH(CH_(3))_(2))` |
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Answer» Correct Answer - A The means of the alkyl subtituents are not in alphabetical order. The correct name is 4-ethyl 3-methylheptane. |
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| 400. |
The correct IUPAC name of the following compound `{:(H_(3)C-CH=C-CH-CH_(3)),(" |"" |"),(" "H_(3)C" "Br):}` isA. 4-bromo-3-methylpent-2-eneB. 2-bromo-3-methylpent-4-eneC. 3-methyl-4-bromopent-4-eneD. 2-bromo-4-methylpent-2-ene |
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Answer» Correct Answer - A `{:(H_(3)overset(1)(C)-overset(2)(C)H=overset(3)(C)-overset(4)(C)H-overset(5)(C)H_(3)),(" |"" |"),(" "H_(3)C" "Br),("4-Bromo-3-methylpent-2-ene"):}` Double bond is given preference |
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