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This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Assertion: Benzyl bromide when kept in acetone water produces benzyl alcohol. Reason: The reaction follows `S_(N)2` mechanism.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true and the reason is the correct explanations of the assertionC. If the assertion is true but reason is falseD. If assertion is false but reason is true. |
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Answer» Correct Answer - A The assertion that on keeping a benzyl bromide in acetone water produces benzyl alcohol is correct. Because `C_(6)H_(5)CH_(2)Br` hydrolyses to produce `C_(6)H_(5)CH_(2)OH`. This conversion is of `S_(N)2` mechanism. |
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| 2. |
The correct statement regarding electrophile is:A. Electrophile is a negatively charged species and can form a bond by accepting of electrons from another electrophileB. Electrophiles are generally neutral species and can form a bond by accepting a pair of electrons from a nucleophileC. Electrophile can be either neutral or positively charged species and can form a bond by accepting pair of electrons from a nucleophileD. Electrphile is a negatively charged species and can form a bond by accepting a pair of electrons from a nucleophile |
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Answer» Correct Answer - C Electrophile can be either neutral or positively charged species and can form a bond by accepting a pair of electron from a nucleophile. |
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| 3. |
Which one of the following pairs represent stereoisomerism?A. Structural and geometrical isomerismB. Linkage and geometrical isomerismC. Chain and rotational isomerismD. Optical and geometrical isomerism |
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Answer» Correct Answer - D Stereoisomerism is of two types: geometrical and optical. |
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| 4. |
Which of the following pairs is an example of position isomerism?A. `CH_(3)-CH_(2)-CH_(2)-CH_(3)` and `CH_(3)-underset(CH_(3))underset(|)(CH)-CH_(3)`B. `CH_(3)-CH_(2)-CH=CH_(2)` and `CH_(3)-CH=CH-CH_(3)`C. `CH_(3)-CH_(2OH` and `CH_(3)-O-CH_(3)`D. `CH_(3)-overset(CH_(3))overset(|)underset(CH_(3))underset(|)(C)-CH_(3)` and `CH_(3)-CH_(2)-CH_(2)-CH_(2)-CH_(3)` |
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Answer» Correct Answer - B `CH_(3)-underset("1-butane")(CH_(2))-CH=CH_(2)` and `CH_(3)-underset("2-butane")(CH)=CH-CH_(3)` |
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| 5. |
Assertion: Staggered form is less stable than the ecliped form Reason: The conformation in which the bond pairs of two central atoms are very far from one another is called stagered form.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true and the reason is the correct explanations of the assertionC. If assertion is true but reason is false.D. If assertion is false but reason is true. |
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Answer» Correct Answer - D The staggered form is more stable than the eclipsed form because the potential energy of staggered form in which the bond pairs of two carbons are far away from each other is minimum. Also the `H`-atoms are as far apart as possible and nonbonded interaction between them is maximum. In occupied form, the `H` -atom are very close and so increased there is an overlap between them and non bonded orbitals are repulsive. that it why staggered form is more stable than occupied form. |
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| 6. |
which one of the following pairs represents the stereoisomerism?A. Geometrical isomerism,position isomerismB. Geometrical isomerism,conformational isomerismC. Optical isomerism,geometrical isomerismD. Optical isomerism,metamerism |
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Answer» Correct Answer - C Optical isomerism and geometrical isomerism. |
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| 7. |
Which of the following compounds may not exist as enantiomers?A. `CH_(3)CH(OH)CO_(2)H`B. `CH_(3)CH_(2)CH(CH_(3))CH_(2)OH`C. `C_(6)H_(5)CH_(2)CH_(3)`D. `C_(6)H_(5)CHClCH_(3)` |
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Answer» Correct Answer - C In `C_(6)H_(5)CH_(2)CH_(3)` chiral centre is absent. |
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| 8. |
If there is no rotation of plane polarized light by a compound in a specific solvent, thought to be chiral, it means that:A. It is certainly mesoB. It is racemic mixtureC. it is certainly not chiralD. no such compound |
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Answer» Correct Answer - A Meso form is optically inactive. In meso compound there is internal compension. |
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| 9. |
n-Propyl alcohol and isopropyl alcohol are examples ofA. Postion isomerismB. Chain isomerismC. tautomerismD. Geometrical isomerism |
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Answer» Correct Answer - A `underset("n-propyl alcohol")(CH_(3)-CH_(2)-CH_(2)-CH_(2)-OH)` and `CH_(3)-underset("Iso-propyl alcohol")underset(OH)underset(|)(CH)-CH_(3)` are position isomers of each other. |
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| 10. |
The isomerism exhibits by alkyl cyanide and alkyl isocyanide isA. FunctionalB. PositionalC. tautomerismD. Metamerism |
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Answer» Correct Answer - A `R-Nvec(=)C` and `R-C-=N` are fuctional isomers. |
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| 11. |
Which of the following group shows `+I` effects?A. `-Br`B. `-COOH`C. `-OR`D. `-COO-` |
| Answer» Correct Answer - D | |
| 12. |
`+m` and `+I` both effects are shown by:A. `-overset(..)underset(..)(O)H`B. `-ddot(N)HCH_(3)`C. `-O^(Theta)`D. `-C(CH_(3))_(3)` |
| Answer» Correct Answer - C | |
| 13. |
Assertion: Nitrenese cannot be isolated. Reason: Nitrenes are the nitrogen analogues of carbeneA. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true and the reason is the correct explanations of the assertionC. If assertion is true but reason is false.D. If assertion is false but reason is true. |
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Answer» Correct Answer - B Assertion is true, reason is true, reason is not a correct explanation for assertion. As nitreanes are too reactive to be isolated. |
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| 14. |
Hyperconjugation involves the overlapping of the following orbitals :A. `p`-and `pi`-orbitalsB. `2pi`-orbitalsC. `d` and `pi`-orbitalsD. `sigma`- and `p`-orbitals |
| Answer» Correct Answer - D | |
| 15. |
In which of the following first resonating structure is more stable than the second?A. `overset(Theta)(CH_(2))-CH=OharrCH_(2)=CH-O^(Theta)`B. `overset(o+)(CH_(2))-O-CH_(3)harrCH_(2)=overset(o+)(O)-CH_(3)`C. `CH_(2)=CH-NH_(2)harroverset(Theta)(CH_(2))-CH=overset(o+)(NH_(2))`D. `overset(o+)(O)-CH=CH_(2)harrO=CH=overset(o+)(CH_(2))` |
| Answer» Correct Answer - C | |
| 16. |
Assertion: `CH_(3)CHO` and `CH_(2)=CHOH` are resonance structures. Reason: Tautomers differ both in the position of atoms as well as electrons.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true and the reason is the correct explanations of the assertionC. If assertion is true but reason is false.D. If assertion is false but reason is true. |
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Answer» Correct Answer - D Assertion false, reason is true. As `CH_(3)CHO` and `CH_(2)=CHOH` are tautomers. |
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| 17. |
Which of the following species cannot show resonance?A. B. C. D. |
| Answer» Correct Answer - A | |
| 18. |
Which of the following species does not have equally contributing resonating structures?A. `CH_(3)-overset(O)overset(||)(C)-O^(Theta)`B. `CH_(2)=CH-CH=CH_(2)`C. D. `CH_(2)=CH-CH_(2)^(o+)` |
| Answer» Correct Answer - D | |
| 19. |
The minimum magnitude of heat of hydrogenation per mole of molecule is of:A. B. C. D. |
| Answer» Correct Answer - D | |
| 20. |
`C-C` bond length in benzene isA. `1.39 Å`B. `1.54 Å`C. `1,34 Å`D. Different in different bonds |
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Answer» Correct Answer - A `C-C` bond length is benzene to act as Lewis acid since they are electron defiecient in nature. However cations such as `Na^(+).K^(+)` etc. (inert gas configuration) have a very little tendency to accept eletrons. Therefore they do not act as Lewis acids in Fridel-Crafts reaction. |
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| 21. |
In which of the following `C=C` bond length is minimum?A. B. C. D. |
| Answer» Correct Answer - B | |
| 22. |
The `C-C` bond length of the following molecules is in the orderA. `C_(2)H_(6) gt C_(2)H_(4) gt C_(6)H_(6) gt C_(2)H_(2)`B. `C_(2)H_(2) lt C_(2)H_(4) lt C_(6)H_(6) lt C_(2)H_(6)`C. `C_(2)H_(6) lt C_(2)H_(2) lt C_(6)H_(6) lt C_(2)H_(4)`D. `C_(2)H_(4) gt C_(2)H_(6) gt C_(2)H_(2) gt C_(6)H_(6)` |
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Answer» Correct Answer - B `{:(underset(1.20Å)(C_(2)H_(2)),lt,underset(1.34Å)(C_(2)H_(2)),lt,underset(1.39 Å)(C_(6)H_(6)),lt,underset(1.54 Å)(C_(2)H_(6))):}` |
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| 23. |
Assertion: Hydroxyketones are not directly used in Grignard reaction. Reason : Griganard reagnts react with hydroxyl group.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true and the reason is the correct explanations of the assertionC. If the assertion is true but reason is falseD. If assertion is false but reason is true. |
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Answer» Correct Answer - A Hydroxy ketones are not directly used in Grignard reagent. Grignard reagents are very reactive. Therefore, they react with hydroxyl group. Hence both are correct. |
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| 24. |
Assertion: Neopentane forms one mono substitutes compound Reason: Neopentane is an isomer of pentane.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true and the reason is not the correct explanations of the assertionC. If assertion is true but reason is false.D. If assertion is false but reason is true. |
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Answer» Correct Answer - B Neopentane is an isomer of pentene and neopentane forms only substitution product. Statement `I` is true, statement `II` is true, statement `II` is not the correct explanation for statement `I`. Neopentane forms mono substituted product due to presence of four identical methyl groups present on carbon atom. |
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| 25. |
Which of the following is not chiral?A. `3`-bromopentaneB. `2`-hydroxy propanoic acidC. `2`-butanolD. `2,3`-dibromopentane |
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Answer» Correct Answer - A `CH_(3)-overset(Br)overset(|)(CH_(2)CH)-CH_(2)-CH_(3)` is not chiral, because of `2` similar groups. |
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| 26. |
The correct order of nucleophilicity isA. `I^(-)gtBr^(-)gtCl^(-)gtF^(-)`B. `I^(-)gtCl^(-)gtBr^(-)gtF^(-)`C. `F^(-)gtCl^(-)gtBr^(-)gtI^(-)`D. `Cl^(-)gtBr^(-)gtF^(-)gtI^(-)` |
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Answer» Correct Answer - A The stronger is the acid, the more is the nucleophilicity of conjugate base. |
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| 27. |
Which of the following is the most stable cation?A. `CH_(3)CH_(2)overset(+)(C)HCH_(3)`B. `CH_(3)-overset(+)underset(CH_(3))(C)CH_(3)`C. `CH_(3)CH_(2)CH_(2)overset(+)(C)H_(2)`D. `CH_(3)^(+)` |
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Answer» Correct Answer - B `(CH_(3))_(3)C^(+)3^(@)` carbonium ion is most stable. |
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| 28. |
Among the following the most stable compound isA. cis-`1,2`-cyclohenediolB. trans-`1,2`-cylcohexanediolC. cis-`1,3`-cyclohenediolD. trans-`1,3`-cyclohexanediol |
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Answer» Correct Answer - D Trans configuration is more stable than cis configuration because in cis-configuration the `H` groups are thrown closely enough together to cause crowding or repulsion. Agrain between `1,2`and `1,3`-configurations, in `1-3`, the `OH` groups are placed further apart to minimise the repulsion. Hence, more stable is `1,3`-configuration. |
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| 29. |
The maximum number of stereoisomers possible for `2`-hydroxy-`2`-methyl butanoic acid isA. `1`B. `2`C. `3`D. `4` |
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Answer» Correct Answer - B `COOH-overset(CH_(3))overset(|)underset(OH)underset(|)(C^(**))-CH_(2)-CH_(3)` One chiral centre. Therfore two forms are possible. |
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| 30. |
Assertion: Stereoisomers which are not mirror image of each other are called diastereomers. Reason: Disasteromers may or may not be optically acitve.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true and the reason is the correct explanations of the assertionC. If assertion is true but reason is false.D. If assertion is false but reason is true. |
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Answer» Correct Answer - B Diastereomer may or may not be optically active. |
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| 31. |
Which of the following biphenyls is optically active?A. B. C. D. |
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Answer» Correct Answer - C `O`-substituted biphenyl are optically active as both the rings are not plane, hence their mirror images are nonsuperimposable. |
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| 32. |
Assertion: Propadiene is optically active. Reason: Propadiene has a plane of symmetry.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true and the reason is the correct explanations of the assertionC. If assertion is true but reason is false.D. If assertion is false but reason is true. |
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Answer» Correct Answer - D `1,2`-propandiene is not optically active because the terminal `2`-hybridised carbons have the same atoms i.e. `H`-atoms. As a result, it has a plane of symmetry passing through the three carbon atoms and hence the molecule is optically inactive. |
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| 33. |
Which one of the following is an optically acitve compound?A. `n-`propanolB. `2`-chloropentaneC. `n`butanolD. `4`-hydroxyheptane |
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Answer» Correct Answer - B `CH_(3)-overset(H)overset(|)underset("2-Chlorobutane")underset(Cl)underset(|)(C^(**))-CH_(2)-CH_(3)` because they contain chiral carbon atom. |
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| 34. |
The optically active tartaric acid is named as `D-(+)-` tartaric acid because it has a positiveA. Optical rotation and is derived from `D`-glucoseB. `pH` in organic solventC. Optical rotation and is derived from `D-(+)-`glyceraldehydeD. Optical rotation when substituted by deuterium. |
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Answer» Correct Answer - C `D(+)`-tartaric acid has positive optical rotation and is derived from `D(+)` glyceraldehyde. |
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| 35. |
Which of the following statements is incorrect?A. The energy of resonance hybrid is always less than that of any resonating structure.B. The resonace energy is the difference between the enthalpies of formation of the molecule and the resonating structure having maximum energy.C. The resonance structures are hypothetical structure and they do not represent any real molecule.D. In delocalized structured of benzenes the `pi`-charge cloud is spread equally above and below the plane of molecule. |
| Answer» Correct Answer - B | |
| 36. |
Which statements about tautomerism is incorrect?A. Tautomers always exist in equilibrium.B. Tautomers can be separated by physical`//` chemical process.C. Tautomerism is a chemical phenomenon which takes place in liquid and gaseous state and catalysed by acid as well as base.D. All tautomers are always functional group isomers. |
| Answer» Correct Answer - D | |
| 37. |
With a change in hybridisation of the carbon bearing the charge, the stability of a carbonion increase in the orderA. `sp lt sp^(2) lt sp^(3)`B. `sp lt sp^(3) lt sp^(2)`C. `sp^(3) lt sp^(2) lt sp`D. `sp^(2) lt sp lt sp^(3)` |
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Answer» Correct Answer - C Stability of carbonion increases with increases in `s`-character of hybrid orbitals of carbon bearing charge, hence correct order is : `sp^(3) lt sp^(2) lt sp`. |
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| 38. |
Which of the following is the correct order of stability of free radicals?A. `"benzyl" gt "allyl" gt 2^(@) gt 1^(@)`B. `"allyl" gt "benzyl" gt 2^(@) gt 1^(@)`C. `"allyl" gt 2^(@) gt 1^(@) gt "benzyl"`D. `"benzyl" gt 2^(@) gt 1^(@) gt "allyl"` |
| Answer» Correct Answer - A | |
| 39. |
Which of the following free radicals would be expected to be most selective?A. `H-C-=overset(.)(C)`B. `H_(2)C=CH^(-)-overset(.)(C)H_(2)`C. `overset(.)(C_(6)H_(5)`D. `overset(.)(C)H_(3)` |
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Answer» Correct Answer - B It is the most stable free radical hence, would be most selective in reaction. |
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| 40. |
The shape of ethylene molecule isA. square planarB. furanC. trigonal planarD. tetrahedral |
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Answer» Correct Answer - C In ethylene molecule carbons are `sp^(2)` hybridised so its structure is trigonal plannar. |
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| 41. |
`S_(N)1` reaction is faster inA. `CH_(3)CH_(2)Cl`B. C. `CH_(3)-overset(CH_(3))overset(|)underset(CH_(3))underset(|)(C)-Cl`D. `CH_(3)-underset(CH_(3))underset(|)underset(CH_(2))underset(|)underset(|)(CH)-Cl` |
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Answer» Correct Answer - C `S_(N)1` mechanism proceeds through carbocation intermediate. `CH_(3)-overset(CH_(3))overset(|)underset(CH_(3))underset(|)(C)-Cl` provides stable carbocation intermediate because it has tertiary carbon. |
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| 42. |
Among the following compound which can be dehydrated vary easily isA. `CH_(3)-CH_(2)-overset(CH_(3))overset(|)underset(OH)underset(|)(C)-CH_(2)-CH_(3)`B. `CH_(3)-CH_(2)-CH_(2)-overset(OH)overset(|)(C)H-CH_(3)`C. `CH_(3)-CH_(2)-CH_(2)-CH_(2)-CH_(2)-OH`D. `CH_(3)-CH_(2)-underset(CH_(3))underset(|)(CH)-CH_(2)-CH_(2)-OH` |
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Answer» Correct Answer - A `{:(CH_(3)-CH_(2)-overset(CH_(3))overset(|)underset(OH)underset(|)(C)-CH_(2)-CH_(3)),(overset(H^(+))toCH_(3)-CH_(2)-overset(CH_(3))overset(|)underset(o+)(C)-CH_(2)-CH_(3)):}` The more stable carbocation is generated thus more easily it will be dehydrated. |
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| 43. |
Which of the following is a chiral compound?A. HexaneB. MethanC. `n`-butaneD. `2,3,4`-trimethyl hexane |
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Answer» Correct Answer - D `CH_(3)-CH_(2)-overset(CH_(3))overset(|)(CH)-overset(CH_(3))overset(|)(CH)-overset(CH_(3))overset(|)(CH)-CH_(3)` it is a chiral compound. |
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| 44. |
Which of the following compounds is not chiral?A. `DCH_(2)CH_(2)CH_(2)Cl`B. `CH_(3)CH_(2)CHDCl`C. `CH_(3)CHDCH_(2)CH_(2)Cl`D. `CH_(2)CHClCH_(2)D` |
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Answer» Correct Answer - A `DCH_(2)-CH_(2)-CH_(2)-Cl` Others are chiral `CH_(3)-CH_(2)-overset(H)overset(|)underset(Cl)underset(|)(C^(**))-D , CH_(3)-overset(H)overset(|)underset(D)underset(|)(C^(**))-CH_(2)-CH_(2)-Cl` `CH_(3)-overset(H)overset(|)underset(Cl)underset(|)(C^(**))-CH_(2)D` |
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| 45. |
Geometrical isomerism is shown inA. `2`-buteneB. `2`-butyneC. `2`-butanolD. Butanal |
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Answer» Correct Answer - A `underset("2-butane")underset(("Cis"))(underset(CH_(3))underset(|)(HC)=underset(CH_(3))underset(|)(CH))` and `underset("2-butane")underset(("Trans"))underset(CH_(3))underset(|)(HC)=overset(CH_(3))overset(|)(CH)` |
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| 46. |
`C_(6)H_(5)C-=N` and `C_(6)H_(5)N-=C` exhibit which type of isomerismA. PositionB. FunctionalC. Dextro isomerismD. Metamerism |
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Answer» Correct Answer - B `C_(6)H_(5)C-=N` and `C_(6)H_(5)Nvec(=)C` are functional isomers. |
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| 47. |
Which of the following compounds shows optical isomerism?A. `CH_(3)CHCl-CH_(2)-CH_(3)`B. `CH_(3)-CH_(2)-CHCl-CH_(2)-CH_(3)`C. `ClCH_(2)-CH_(2)-CH_(2)-CH_(3)`D. `ClCH_(2)-CH_(2)-CH_(3)` |
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Answer» Correct Answer - A `CH_(3)-overset(H)overset(|)underset(Cl)underset(|)(C^(**))-CH_(2)-CH_(3)` In other compound chiral carbon is absent. |
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| 48. |
`n`-butane and isobutane are examples ofA. Chain isomersB. Geometrical isomersC. Position isomersD. Tautormers |
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Answer» Correct Answer - A `CH_(3)-underset("n-butante")(CH_(2))-CH_(2)-CH_(3)` and `CH_(3)-underset("Iso-butane")underset(CH_(3))underset(|)(CH)-CH_(3)` |
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| 49. |
Statement I: Molecules that are non-superimposable on their mirror images are chiral. Statement II: All chiral molecules have chiral centres.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true and the reason is the correct explanations of the assertionC. If the assertion is true but reason is falseD. If assertion is false but reason is true. |
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Answer» Correct Answer - C `2,3` pestadiene has no chiral carbon but chiral molecule. |
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| 50. |
Number of isomers of `C_(4)H_(10)` isA. `2`B. `3`C. `4`D. Isomerism not exist |
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Answer» Correct Answer - a `CH_(3)-underset("n-butane")(CH_(2))-CH_(2)-CH_(3)` `CH_(3)-underset("Iso-butane")underset(CH_(3))underset(|)(CH)-CH_(3)` |
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