MCQOPTIONS
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MCQOPTIONS
This section includes 31 Mcqs, each offering curated multiple-choice questions to sharpen your Chemistry knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
All bonds in benzene are equal due to [Roorkee 1990; KCET 1998] |
| A. | Tautomerism |
| B. | Inductive effect |
| C. | Resonance |
| D. | Isomerism |
| Answer» D. Isomerism | |
| 2. |
Which is the most stable carbocation [J & K 2005] |
| A. | iso-propyl |
| B. | Triphenylmethyl cation |
| C. | Ethyl cation |
| D. | \[\pi \]-propyl cation |
| Answer» C. Ethyl cation | |
| 3. |
In \[C{{H}_{3}}C{{H}_{2}}OH,\] the bond that undergoes heterolytic cleavage most readily is [IIT-JEE 1988] |
| A. | C - C |
| B. | C - O |
| C. | C - H |
| D. | O - H |
| Answer» E. | |
| 4. |
In which of the following species the central C-atom is negatively charged [NCERT 1985] |
| A. | Carbanion |
| B. | Carbonium ion |
| C. | Carbocation |
| D. | Free radical |
| Answer» B. Carbonium ion | |
| 5. |
Which of the following resonating structures of 1-methoxy-1, 3-butadiene is least stable [IIT Screening 2005] |
| A. | \[\overset{}{\mathop{C}}\,{{H}_{2}}-CH=CH-CH=\overset{\oplus }{\mathop{O}}\,-C{{H}_{3}}\] |
| B. | \[C{{H}_{2}}=C{{H}_{2}}-\overset{}{\mathop{C}}\,H-CH=\overset{\oplus }{\mathop{O}}\,-C{{H}_{3}}\] |
| C. | \[\overset{}{\mathop{C}}\,{{H}_{2}}-\overset{\oplus }{\mathop{C}}\,H-CH=CH-O-C{{H}_{3}}\] |
| D. | \[C{{H}_{2}}=CH-\overset{}{\mathop{C}}\,H-\overset{\oplus }{\mathop{C}}\,H-O-C{{H}_{3}}\] |
| Answer» D. \[C{{H}_{2}}=CH-\overset{}{\mathop{C}}\,H-\overset{\oplus }{\mathop{C}}\,H-O-C{{H}_{3}}\] | |
| 6. |
Credit for the ring structure of benzene goes to [RPET 1999] |
| A. | Wholer |
| B. | Faraday |
| C. | Kekule |
| D. | Baeyer |
| Answer» D. Baeyer | |
| 7. |
Among the following the dissociation constant is highest for [AIIMS 2004] |
| A. | \[{{C}_{6}}{{H}_{5}}OH\] |
| B. | \[{{C}_{6}}{{H}_{5}}C{{H}_{2}}OH\] |
| C. | \[C{{H}_{3}}C\equiv CH\] |
| D. | \[C{{H}_{3}}NH_{3}^{+}C{{l}^{-}}\] |
| Answer» E. | |
| 8. |
Which of the following statements is not characteristic of free radical chain reaction [JIPMER 1997] |
| A. | It gives major product derived from most stable free radical |
| B. | It is usually sensitive to change in solvent polarity |
| C. | It proceeds in three main steps like initiation, propagation and termination |
| D. | It may be initiated by U.V. light |
| Answer» C. It proceeds in three main steps like initiation, propagation and termination | |
| 9. |
In the reaction \[C{{H}_{3}}CHO+HCN\to C{{H}_{3}}CH(OH)CN\]a chiral centre is produced. This product would be [CBSE PMT 1995] |
| A. | Laevorotatory |
| B. | Meso compound |
| C. | Dextrorotatory |
| D. | Racemic mixture |
| Answer» E. | |
| 10. |
The C - C bond length of the following molecules is in the order [IIT-JEE 1991] |
| A. | \[{{C}_{2}}{{H}_{6}}>{{C}_{2}}{{H}_{4}}>{{C}_{6}}{{H}_{6}}>{{C}_{2}}{{H}_{2}}\] |
| B. | \[{{C}_{2}}{{H}_{2}}<{{C}_{2}}{{H}_{4}}<{{C}_{6}}{{H}_{6}}<{{C}_{2}}{{H}_{6}}\] |
| C. | \[{{C}_{2}}{{H}_{6}}>{{C}_{2}}{{H}_{2}}>{{C}_{6}}{{H}_{6}}>{{C}_{2}}{{H}_{4}}\] |
| D. | \[{{C}_{2}}{{H}_{4}}>{{C}_{2}}{{H}_{6}}>{{C}_{2}}{{H}_{2}}>{{C}_{6}}{{H}_{6}}\] |
| Answer» C. \[{{C}_{2}}{{H}_{6}}>{{C}_{2}}{{H}_{2}}>{{C}_{6}}{{H}_{6}}>{{C}_{2}}{{H}_{4}}\] | |
| 11. |
With a change in hybridisation of the carbon bearing the charge, the stability of a carbanion increase in the order [DCE 2003] |
| A. | \[sp<s{{p}^{2}}<s{{p}^{3}}\] |
| B. | \[sp<s{{p}^{3}}<s{{p}^{2}}\] |
| C. | \[s{{p}^{3}}<s{{p}^{2}}<sp\] |
| D. | \[s{{p}^{2}}<sp<s{{p}^{3}}\] |
| Answer» D. \[s{{p}^{2}}<sp<s{{p}^{3}}\] | |
| 12. |
Which of the following has the highest nucleophilicity [IIT-JEE Screening 2000] |
| A. | \[{{F}^{-}}\] |
| B. | \[O{{H}^{-}}\] |
| C. | \[CH_{3}^{-}\] |
| D. | \[NH_{2}^{-}\] |
| Answer» D. \[NH_{2}^{-}\] | |
| 13. |
Which of the following act as nucleophiles [Roorkee 1999] |
| A. | \[C{{H}_{3}}N{{H}_{2}}\] |
| B. | \[R{{O}^{-}}\] |
| C. | \[AlC{{l}_{3}}\] |
| D. | \[C{{H}_{3}}MgBr\] |
| Answer» B. \[R{{O}^{-}}\] | |
| 14. |
How many carbon atoms in the molecule \[HCOO-{{(CHOH)}_{2}}-COOH\]are asymmetric [MP PET 2001] |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | None of these |
| Answer» C. 3 | |
| 15. |
Which one of the following species is most stable [IIT-JEE 1995] |
| A. | \[p-{{O}_{2}}N-{{C}_{6}}{{H}_{4}}-\overset{+}{\mathop{C}}\,{{H}_{2}}\] |
| B. | \[p-C{{H}_{3}}O-{{C}_{6}}{{H}_{4}}-\overset{+}{\mathop{C}}\,{{H}_{2}}\] |
| C. | \[p-Cl-{{C}_{6}}{{H}_{4}}-\overset{+}{\mathop{C}}\,{{H}_{2}}\] |
| D. | \[{{C}_{6}}{{H}_{5}}-\overset{+}{\mathop{C}}\,{{H}_{2}}\] |
| Answer» C. \[p-Cl-{{C}_{6}}{{H}_{4}}-\overset{+}{\mathop{C}}\,{{H}_{2}}\] | |
| 16. |
Most stable carbonium ion is [Pb. CET 2004] |
| A. | \[{{\overset{+}{\mathop{C}}\,}_{2}}{{H}_{5}}\] |
| B. | \[{{(C{{H}_{3}})}_{3}}\overset{+}{\mathop{C}}\,\] |
| C. | \[{{({{C}_{6}}{{H}_{5}})}_{3}}\overset{+}{\mathop{C}}\,\] |
| D. | \[{{C}_{6}}{{H}_{5}}\overset{+}{\mathop{C}}\,{{H}_{2}}\] |
| Answer» D. \[{{C}_{6}}{{H}_{5}}\overset{+}{\mathop{C}}\,{{H}_{2}}\] | |
| 17. |
Which of the following compounds are not arranged in order of decreasing reactivity towards electrophilic substitution [DCE 2003] |
| A. | Fluoro benzene > chloro benzene > bromo benzene |
| B. | Phenol > n-propyl benzene > benzoic acid |
| C. | Chloro toluene > para-nitro toluene > 2-chloro-4-nitro toluene |
| D. | Benzoic acid > phenol > n-propyl benzene |
| Answer» E. | |
| 18. |
Which are the staggered forms of ethane |
| A. | 1 and 4 |
| B. | 3 and 4 |
| C. | 2 and 4 |
| D. | 1 and 3 |
| Answer» D. 1 and 3 | |
| 19. |
The following reaction is described as [CBSE PMT 1997] \[\begin{matrix} C{{H}_{3}}{{(C{{H}_{2}})}_{5}}\\ {}\\ {{H}_{3}}C\\ \end{matrix}>\underset{H}{\mathop{\underset{|}{\mathop{C}}\,}}\,-Br\xrightarrow{OH}HO-\underset{H}{\mathop{\underset{|}{\mathop{C}}\,}}\,<\begin{matrix} {{(C{{H}_{2}})}_{5}}C{{H}_{3}}\\ {}\\ C{{H}_{3}}\,\,\,\,\,\,\,\,\,\,\,\\ \end{matrix}\] |
| A. | \[S{{E}^{2}}\] |
| B. | \[S{{N}^{1}}\] |
| C. | \[S{{N}^{2}}\] |
| D. | \[S{{N}^{0}}\] |
| Answer» D. \[S{{N}^{0}}\] | |
| 20. |
Among the following compounds (I-III) the correct order of reaction with electrophilic reagent is [CBSE PMT 1997] |
| A. | II > III > I |
| B. | III < I < II |
| C. | I > II > III |
| D. | I = II > III |
| Answer» D. I = II > III | |
| 21. |
The optically active tartaric acid is named asD-(+)- tartaric acid because it has a positive [IIT-JEE 1999] |
| A. | Optical rotation and is derived from D-glucose |
| B. | pH in organic solvent |
| C. | Optical rotation and is derived from D(+) glyceraldehyde |
| D. | Optical rotation only when substituted by deuterium |
| Answer» D. Optical rotation only when substituted by deuterium | |
| 22. |
The number of possible isomers for compound \[{{C}_{2}}{{H}_{3}}C{{l}_{2}}Br\] is [MP PMT 1999] |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 5 |
| Answer» C. 4 | |
| 23. |
The compound in which carbon uses only its \[s{{p}^{3}}\] hybrid orbitals for bond formation is [IIT-JEE 1989] |
| A. | \[HCOOH\] |
| B. | \[{{(N{{H}_{2}})}_{2}}CO\] |
| C. | \[{{(C{{H}_{3}})}_{3}}COH\] |
| D. | \[{{(C{{H}_{3}})}_{3}}CHO\] |
| Answer» D. \[{{(C{{H}_{3}})}_{3}}CHO\] | |
| 24. |
Which one of the following does not have \[s{{p}^{2}}\] hybridised carbon [AIEEE 2004] |
| A. | Acetonitrile |
| B. | Acetic acid |
| C. | Acetone |
| D. | Acetamide |
| Answer» B. Acetic acid | |
| 25. |
How many p-bonds are present in naphthalene molecule [RPMT 2002] |
| A. | 3 |
| B. | 4 |
| C. | 5 |
| D. | 6 |
| Answer» D. 6 | |
| 26. |
Which of the following hybridisation has highest percentage of s-character [BHU 1986] |
| A. | \[s{{p}^{3}}\] |
| B. | \[s{{p}^{2}}\] |
| C. | \[sp\] |
| D. | None of these |
| Answer» D. None of these | |
| 27. |
Acetylene molecule has carbon in [Kerala (Engg.) 2002] |
| A. | \[sp\]- hybridisation |
| B. | \[s{{p}^{2}}\]- hybridisation |
| C. | \[s{{p}^{3}}\]- hybridisation |
| D. | \[s{{p}^{3}}d\]- hybridization |
| Answer» B. \[s{{p}^{2}}\]- hybridisation | |
| 28. |
Conjugated double bond is present in [RPMT 1999; JIPMER 2001] |
| A. | 1, 2-butadiene |
| B. | 1, 3-butadiene |
| C. | 1, 3-pentadiene |
| D. | \[\beta \]-butylene |
| Answer» C. 1, 3-pentadiene | |
| 29. |
The hybridization involved in the six carbon atoms of benzene is [BHU 1999] |
| A. | \[3s{{p}^{3}},\,\,3s{{p}^{2}}\] |
| B. | \[3s{{p}^{3}},\,\,3sp\] |
| C. | All \[6sp\] |
| D. | All \[6s{{p}^{2}}\] |
| Answer» E. | |
| 30. |
The number of \[\pi \] bonds in 3-hexyne-1-ene is [MP PMT 1999] |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» D. 4 | |
| 31. |
In which of the compounds given below is there more than one kind of hybridisation \[(sp,\text{ }s{{p}^{2}},\text{ }s{{p}^{3}})\] for carbon (i) \[C{{H}_{3}}C{{H}_{2}}C{{H}_{2}}C{{H}_{3}}\] (ii) \[C{{H}_{3}}-CH=CH-C{{H}_{3}}\] (iii) \[C{{H}_{2}}=CH-CH=C{{H}_{2}}\] (iv) \[H-C\equiv C-H\] [CBSE PMT 1995] |
| A. | (ii) and (iv) |
| B. | (i) and (iv) |
| C. | (ii) and (iii) |
| D. | (ii) |
| Answer» E. | |